The National Institutes of Health (NIH) announced today that Dr. Francis S. Collins will step down as director of the agency.

Collins, the longest-serving presidentially-appointed NIH director, decided to end his tenure by the end of the year. He had served three U.S. presidents over more than 12 years.

NIH did not announce a successor to Collins or a timeline for appointing one.

“It has been an incredible privilege to lead this great agency for more than a decade,” Collins said in a news release. “I love this agency and its people so deeply that the decision to step down was a difficult one, done in close counsel with my wife, Diane Baker, and my family. I am proud of all we’ve accomplished. I fundamentally believe, however, that no single person should serve in the position too long, and that it’s time to bring in a new scientist to lead the NIH into the future.

“I’m most grateful and proud of the NIH staff and the scientific community, whose extraordinary commitment to lifesaving research delivers hope to the American people and the world every day.”

Collins took office as the NIH’s 16th director in August 2009 after being appointed by President Barack Obama. He was asked to continue in the role by President Donald Trump when he took office in 2017, then again by President Joe Biden earlier this year. Before serving as NIH director, Collins was director of the National Human Genome Research Institute (NHGRI) from 1993-2008.

“Few people could come anywhere close to achieving in a lifetime what Dr. Collins has at the helm of NIH,” Health and Human Services Secretary Xavier Becerra said. “It takes an extraordinary person to tackle the biggest scientific challenges facing our nation — and under three presidents, amidst three distinctly different chapters of American history. Dr. Collins, master of scientific breakthroughs and scientific reason — from mapping the human genome to fighting the most devastating pandemic of a century — has routinely broken ground to save countless lives, while unleashing innovation to benefit humanity for generations to come.”

According to the NIH, Collins will continue to lead his NHGRI research laboratory that is pursuing genomics, epigenomics and single cell biology to understand the causes and means of prevention for type 2 diabetes. The lab also aims to develop new genetic therapies for the most dramatic form of premature aging, Hutchinson-Gilford Progeria Syndrome.