Boris Nikolic is a Croatian-trained physician specializing in immunology and transplantation. He earned his MD from Zagreb Medical School and completed clinical training at the University of Zagreb Medical Centre in Croatia. In 1994, he entered the Harvard Graduate Program in Immunology, followed by a postdoctoral fellowship in transplantation immunology. He held academic positions at Harvard Medical School, including Instructor in Surgery, Instructor in Medicine, and Assistant Professor in Medicine. From 2002, he founded and directed the Advanced Immunology Laboratory for Tolerance Induction Stem Cell Transplantation at the Renal Unit of Massachusetts General Hospital-Harvard Medical School. Since 2007, he has been on leave from his Harvard faculty position. Nikolic transitioned into venture capital and advisory roles, serving as chief advisor for science and technology to Bill Gates. He is the Managing Director and Co-Founder of Biomatics Capital Partners, focusing on biotech investments. In 2019, he was named as a potential backup executor in Jeffrey Epstein's will, though he stated he had no prior involvement with Epstein's estate and declined the role.