Stephen Friend is out at Apple's health team, after just over a year at the company, according to people familiar with the matter.
Friend's specialty involves rethinking health care research, with a focus on creating open incentives and standards that benefit patients. That was the mission of Sage Bionetworks, a non-profit that he co-founded in 2009 as a spinout of Merck.
Friend is also a cancer researcher, and he served on the faculty at Harvard Medical School.
The news that he joined Apple in 2016 to work on the "health-related projects" caused waves in the health industry given his stature. Apple at the time had introduced software frameworks -- ResearchKit, CareKit and HealthKit -- which are designed to help developers and consumers access health information.
These software kits required Apple to meet rigorous standards around security, privacy and consent, which are within Friend's realm of expertise.
Since then, Apple has launched a medical records beta with the support of a dozen leading hospitals to aggregate all of this health information in one place. It has also hired Sumbul Desai, a former executive director of Stanford's center for digital health.
Another member of Apple's health team, Anil Sethi, also left the company at the end of 2017 to work on a start-up focused on gathering health information for cancer patients.
Apple's COO Jeff Williams is also passionate about health care. He recently said that he envisioned the future as "consumers owning their health data," which isn't the reality for millions of Americans today.
Friend did not respond to a request for comment from CNBC. However, his LinkedIn page has been updated to show that his tenure at Apple ended in November of 2017, and he now lists himself as an "independent entrepreneur."