Our Team

Eric Lefkofsky is the founder and Chief Executive Officer at Tempus, a leader in artificial intelligence and precision medicine. He is the co-founder and General Partner of Lightbank, a private venture capital firm specializing in investments in technology companies. He is also the co-founder of Pathos AI, a clinical stage biotechnology company focused on re-engineering drug development; Groupon (NASDAQ: GRPN), a global e-commerce marketplace; Mediaocean, a leading provider of integrated media procurement technology; Echo Global Logistics (NASDAQ: ECHO), a technology-enabled transportation and logistics outsourcing firm; and InnerWorkings (NASDAQ: INWK), a global provider of managed print and promotional solutions.

He co-chairs the Lefkofsky Family Foundation with his wife Liz to advance high-impact initiatives that enhance lives in the communities served. Lefkofsky also serves on the board of directors of The Art Institute of Chicago and Northwestern Medicine. He holds a bachelor’s degree from the University of Michigan and a J.D. from the University of Michigan Law School.

Christina Antoniou serves as Senior Vice President, Head of Corporate Development at Tempus, where she is responsible for the company’s mergers, acquisitions, partnerships and strategic investing efforts. Christina has extensive experience executing strategic and financial transactions in the healthcare industry. Before joining Tempus, Christina spent four years at Medidata Solutions, a Dassault Systèmes company. There, she held multiple roles, including Vice President, Head of Integration and Senior Director, Corporate Development. At Medidata, Christina completed several strategic acquisitions and early-stage investments. Later she represented Medidata in its sales process, culminating in the sale of Medidata to Dassault Systèmes for $5.8 billion. After the acquisition, Christina led Medidata’s integration with Dassault Systèmes. Earlier in her career, Christina held roles in investment banking and venture capital. Christina received an MBA from the Wharton School and holds a BA from Smith College.

Dr. Cohen is a leading medical oncologist and cancer researcher who brings a unique combination of extensive clinical and research experience to Tempus’ leadership team. He was most recently the Chief of the Division of Hematology-Oncology as well as the Associate Director of Clinical Science at UC San Diego (UCSD) Moores Cancer Center. Dr. Cohen also led the Precision Immunotherapy Clinic and co-directed the San Diego Center for Precision Immunotherapy at UCSD. Before UCSD, Dr. Cohen spent 15 years at the University of Chicago, where he was the co-director of the Head and Neck Cancer Program as well as Hematology/Oncology Fellowship Program Director.

Shane Colley is the Chief Technology Officer at Tempus. Prior to joining Tempus, Colley was Vice President of Research and Development at R1 RCM (formerly Accretive Health), where he built and led a global organization of over 200 product, architecture, design, and development professionals that were responsible for R1’s technology portfolio. Colley earned his Bachelor of Science in Computer Science from Iowa State University.

Robyn serves as Tempus’ Chief Privacy Officer, where she regularly counsels on a wide range of matters that include state and federal data privacy and security compliance, international privacy and security, and data breach response. Prior to joining Tempus, Robyn served as VP, Chief Privacy & Counsel at Allscripts (now Veradigm) and the HIPAA Privacy Officer for Aon. Additionally, Robyn has worked for multiple, international law firms where she worked on transactional matters including representing hospitals, dental management companies, and pharmaceutical, medical device, and nutritional supplement companies. Robyn began her career at the United States Department of Health and Human Services, Office of Inspector General. She holds a BA from the University of Illinois, Urbana-Champaign in History and Political Science, a JD from Chicago-Kent College of Law, a Master of Public Health from Boston University where she served as the Health Law, Bioethics and Human Rights Fellow and a Certificate in Business Practices from Northwestern University.

Laura Elster serves as Chief Commercial Officer, Diagnostics, where she leads Tempus’ commercial and field medical organizations focused on delivering AI-enabled diagnostics and precision medicine solutions to health systems and providers across multiple clinical verticals, as well as life sciences partners across pharma and biotech. In this role, she oversees both clinical sales for providers and diagnostic services for life sciences, helping ensure Tempus’ diagnostics and technology translate into meaningful impact for patients and drug development.
Laura has been with Tempus since its earliest days and has played a central role in building and scaling the company’s provider commercial organization over the past decade, helping grow it from a startup team into a multi-vertical, national operation supporting multiple clinical specialties and markets. Prior to joining Tempus, Laura spent more than 13 years at St. Jude Medical, Inc., providing clinical services and working closely with care teams to improve patient outcomes in cardiac electrophysiology. Laura holds a Bachelor of Science in Biomedical Engineering from Washington University in St. Louis.

Greg is Tempus’ Chief Information Security Officer, responsible for leading the Information Security team, managing information security risks, and protecting data integrity and privacy. Prior to joining Tempus, Greg led the Global Security Operations team at the Whirlpool Corporation, a leading manufacturer of home appliances. Greg earned his Bachelor of Science in Information Technology from Colorado State University.

Ryan Fukushima builds AI systems that shift healthcare from reactive treatment to proactive, personalized care. As Chief Executive Officer, Data & Apps at Tempus AI, he's building an Intelligence Engine that generates clinical insights at the speed of thought.

From Day 1, Ryan has scaled Tempus from startup to public company, organizing multimodal healthcare data, distributing clinical-grade AI applications across thousands of sites and partnering with hundreds of biopharmaceutical companies.

With engineering roots and venture experience at Lightbank, Ryan brings technical depth and business acumen to healthcare's AI transformation. He holds a BS in Engineering from Cal Poly and an MBA from Michigan Ross (Zell Scholar).

Stacey is Tempus’ Chief People Officer, responsible for leading the People Operations team, driving a culture that inspires and motivates the entire team to deliver on our mission of improving patient outcomes. Prior to joining Tempus, Stacey was the Chief People Officer at Enova International, a leading FinTech company in Chicago. Stacey’s 20 years of HR leadership experience has been tested and validated in fast-paced, high-growth technology and professional services industries in private and public companies and non-profit institutions such as Groupon, Enova, Thomson Reuters, and the Museum of Science & Industry. She holds a BA in Geography from Indiana University and is an inspired breast cancer survivor.

Dr. Halla Nimeiri serves as the Chief Development Officer of Oncology at Tempus. Prior to Tempus, she held clinical development positions at Foundation Medicine and AbbVie. Dr. Nimeiri is a dedicated oncologist. She brings expertise in clinical trial design, drug development, and precision oncology. Dr. Nimeiri is an active academic clinician at Feinberg School of Medicine, where she provided transformative patient care for over 10 years. Dr. Nimeiri earned her dual fellowship in Hematology/Oncology from The University of Chicago.

Erik Phelps serves as Executive Vice President and Chief Administrative and Legal Officer at Tempus. He oversees various functions within the company, including legal, quality, compliance, corporate risk, and external affairs in addition to working closely with communications and human resources. Prior to joining Tempus, he was the General Counsel at Epic, a software company that provides electronic health records for medical groups, hospitals and healthcare organizations. Prior to his time there, he served as a partner at Michael Best & Friedrich LLP in Madison, WI where he focused on software licensing and technology-related work, including work with early-stage companies. He earned a bachelor’s degree from Beloit College and his J.D. from George Washington University Law School.

Andy Polovin serves as General Counsel at Tempus, where he oversees and is responsible for various legal and business issues. Prior to joining Tempus, Andy was the General Counsel of Uptake Technologies, Inc., a company specializing in Artificial Intelligence software for heavy industry. Andy has also served as an Assistant United States Attorney focusing on narcotics and white-collar crime investigations; an equity partner at Bartlit Beck, one of the nation’s leading trial boutiques; and a Law Clerk to the Chief Judge of the U.S. Court of Appeals for the Seventh Circuit. Andy graduated from Colgate University and earned his law degree from Northwestern University School of Law.

Jim Rogers serves as Chief Financial Officer at Tempus, where he is responsible for overseeing the Company’s Accounting, FP&A, Treasury, and Investor Relations’ functions.  Prior to joining Tempus, Jim held various finance positions at Groupon, including leading FP&A for the North America business and serving as the financial controller of Asia Pacific operations.  Prior to Groupon, Jim was part of Ernst & Young’s assurance practice, where he worked with various financial services firms.  Jim earned his B.B.A. in Accounting from the University of Notre Dame and his MS in Accounting from Northern Illinois University.

Dr. Kate Sasser is the Chief Scientific Officer of Tempus. Dr. Sasser brings over 20 years of experience in translational research and precision medicine in biological sciences across academia and the pharmaceutical and biotech industry. Prior to Tempus, she led the translational research, precision medicine, and R&D operations organizations within Genmab, a biotech company focused on developing transformative antibody therapeutics as medicine. She also led translational research for oncology at Johnson and Johnson (Janssen PRD), using translational and data science approaches to accelerate clinical development. Dr. Sasser graduated from Oregon State University with a BS in Microbiology, and received her PhD in integrated biomedical sciences from Ohio State University.

Tom Schoenherr is the Chief Executive Officer of Diagnostics at Tempus. He leads the strategic vision and operations of a global organization dedicated to advancing patient care. Prior to joining Tempus, Tom served as CEO of Ambry Genetics from 2021 to 2025 and previously as Chief Commercial Officer from November 2017 to 2021. Ambry Genetics was acquired by Tempus in 2025. He has over 25 years of commercial experience in biotechnology, specifically molecular diagnostics, with a solid track record in building high-growth companies. Before joining Ambry, Tom led Counsyl’s commercial strategy and was responsible for driving business growth and increasing market share in the very competitive carrier screening space. He served in similar leadership roles at Quest, Siemens Healthcare, and Abbott Diagnostics, as well as having served on several advisory boards providing leadership and guidance to management teams and company founders on their organizational goals and strategies of businesses to access and determine potential opportunities. Tom is an advocate in the relentless pursuit of new and better ways of working, empowering organizations and teams to embrace digital transformation and telemedicine to generate new and significant value for consumers and shareholders. His passion truly lies in ensuring patients around the world have access to transformational medical options.

Tom earned his BS from Michigan State University and completed his Executive Business Development Program from the University of Notre Dame.

Chris Scotto DiVetta serves as the Senior Vice President & General Manager, AI Applications. Prior to Tempus, Chris worked as VP & General Manager at Quest Diagnostics where he established their Genomics and Pharma Services businesses as well as led their Neurology business unit that launched the first accessible blood based dementia diagnostic. Chris has had General Manager, Product Management, and technology leadership roles at NVIDIA and GE Healthcare focused on building smart medical devices and diagnostics by leveraging advancements in AI. Chris holds a B.S. in Computer Engineering and an MBA, from the University of Wisconsin-Madison.

Lauren Silvis serves as Senior Vice President of External Affairs at Tempus, overseeing regulatory, public policy, government affairs and strategic communications. She has held a number of senior career public health roles, serving as a Senior Advisor at the Department of Health and Human Services, Chief of Staff of the Food and Drug Administration and Deputy Center Director for Policy in FDA’s Center for Devices and Radiological Health. She currently serves as a member of the Council of Councils for the National Institutes of Health. During her time in government, she advanced policies to promote innovation in precision medicine, real world evidence, clinical trials and digital health. Lauren serves as Board Vice Chair for the Personalized Medicine Coalition and a board member for the Real-World Evidence Alliance. Earlier in her career, she was a partner at the international law firm Sidley Austin LLP, focusing on regulation of pharmaceuticals and medical devices. Lauren graduated from Duke University and earned her law degree from Georgetown University Law Center.

Dr. Slavin is a physician-scientist and biotech executive who brings a deep background in clinical genetics and molecular diagnostics to the Tempus leadership team. As the Chief Medical Officer of Diagnostics, he draws on his industry experience and expertise in clinical genetics, molecular diagnostics, and pediatrics. Before joining Tempus, he held key leadership roles as the Chief Clinical Officer of Molecular Oncology at Quest Diagnostics and Chief Medical Officer at Myriad Genetics. He was an assistant professor in the department of Medical Oncology at City of Hope National Medical Center, where he continues to teach in their hereditary genomics program. A dedicated researcher, he has published over 85 journal articles and has been involved in many national cancer research grants, including those from the NIH.

Patty serves as Chief Marketing Officer, Data & Apps at Tempus, where she is responsible for the company’s Marketing and Communications strategy and functions. Prior to joining Tempus, Patty was Vice President of Growth Marketing at Livongo / Teladoc, a global leader in whole person virtual care. At Livongo, Patty founded and scaled the Growth Marketing team that drove innovation and generated significant growth. After Livongo’s merger with Teladoc, Patty led the Growth Marketing team for the combined company. Prior to Livongo, Patty held various marketing leadership roles at Abbott, launching innovative technologies globally. Earlier in her career, Patty held different roles at technology and medical devices companies. Patty received a Master in Business Administration from Stanford Graduate School of Business and a bachelor’s degree in Telecommunications Engineering from ORT University, in Uruguay.

Melisa Tucker serves as the Chief Data Officer at Tempus AI, where she leads initiatives to acquire and harness multimodal data to advance patient care, research and artificial intelligence. She brings deep expertise in health data and AI to the role, having previously led the Real-World Evidence business at Flatiron Health, an oncology data company acquired by Roche. Melisa also served as Chief Product Officer at Nym Health, an AI-enabled medical coding platform, and oversaw research products at Verily Life Sciences (part of Alphabet). Earlier in her career, she worked in early-stage venture capital and at McKinsey & Company. Melisa holds an MBA from Harvard Business School and an A.B. in Chemistry magna cum laude from Princeton University.

Shane Woods serves as Chief Strategy Officer & GM, Data Products at Tempus, where he is responsible for accelerating strategic customer partnerships and incubating new business ventures. With two decades of experience in oncology, Shane has a proven track record of growth and innovation. Prior to joining Tempus, he served as Chief Commercial Officer at Flatiron Health, where he founded and scaled the commercial functions. At Flatiron, he built enduring enterprise partnerships across the top 20 oncology biopharma. Earlier in his career, Shane held leadership positions in life science consulting, leveraging his scientific expertise in precision medicine. Shane is a scientist by training, having completed research appointments in cancer biology at academic institutions, including Harvard Medical School and the University of Notre Dame. Shane earned a doctorate in genetics from the University of Cambridge where he was a Bill Gates Scholar and graduated with honors in biochemistry from Queen’s University in Canada.

Mike Yasiejko serves as President of Diagnostics at Tempus, where he leads growth strategy, portfolio and commercial operations for provider and industry partner collaborations. He previously served as Chief Commercial Officer and General Manager of Genomics. Prior to Tempus, Mike was an Associate Partner at Bain and Company, supporting clients across multiple industries and functions. He also advises early-stage emerging technology ventures. Mike received a bachelor’s degree with honors in Engineering from Virginia Tech and earned an MBA from the University of Chicago Booth School of Business.

Razik Yousfi is the Senior Vice President and General Manager of AI Products at Tempus, where he leads multi-modal Foundation Model initiatives and the development of AI products for Life Sciences and clinical care. He previously served as CEO and CTO of Paige AI, a pioneer in AI for computational pathology, through its acquisition by Tempus in 2025. Razik is recognized for bridging deep technical expertise with executive leadership to deliver high-impact, AI-enabled solutions. A proponent of lean product development, he specializes in building and motivating cross-functional teams to solve complex problems. He is driven by a passion for creating customer-centric products at the intersection of data and AI—ultimately advancing a new generation of precision medicine tests that improve patient outcomes.

“We are thrilled to have led an investment in Tempus... Given NEA's long and successful history investing in the intersection of technology and life science, we felt like the perfect strategic partner given Tempus' mission to help doctors personalize care by collecting and analyzing large volumes of data.”

“The next major evolution in health care will be the embrace of data to dramatically improve patient outcomes, and I believe Tempus is the company that is best positioned to lead this transition. The team at Tempus is exceptional, and as committed to the mission as can be.”

“I look forward to working with the Tempus team as they continue to apply technology and artificial intelligence to healthcare, deploying intelligent diagnostics that enhance research, empower physicians, and positively change the lives of patients.”

“Tempus has developed a distinct set of solutions that has real potential to revolutionize cancer care. I look forward to working with the leadership team in developing those offerings to provide even more value to the company, its partners, and ultimately patients.”

“As a surgical oncologist, I have worked to reduce racial, ethnic and gender health care disparities throughout my career. Tempus is a leader in the field of data-driven medicine, and I am excited to work with their team to further enhance patient outcomes for individuals of all backgrounds and from all communities.”

“I'm honored to be working with the Tempus team as they advance innovative tools for personalizing patient care and empower providers with information that can help them make better and more informed treatment decisions for their patients.”

“Having spent my entire career at the forefront of emerging technologies, it’s exciting to see how healthcare is finally embracing the very technologies that have transformed so many other industries. This is a space that is near and dear to me, and I'm excited to be a part of Tempus as they seek to bring big data, artificial intelligence and advanced molecular analysis to those suffering with cancer and other life threatening diseases.”

"It is an honor to serve with the Tempus team — professionals with a passion to transform healthcare through technology that facilitates patients rapidly getting the best treatment available for their unique situations; to relieve their suffering, improve their health and save their lives.”