Mark Barnard, Howard Hughes Medical InstituteThe Howard Hughes Medical Institute’s (HHMI) health care and endowment fund has lost its private investments chief.

Mark Barnard will step down as managing director of private investments for the $18.2 billion fund effective June 2016, the institute announced. He will stay on as a part-time advisor to the endowment through the end of November.

“It’s been an honor and a privilege to have worked with HHMI all of these years and been part of an investment team and created investment returns in support of the institute’s incredible mission of scientific research and education,” Barnard said in a statement.

Upon retiring from the Chevy Chase, Maryland-based fund, he said he will open “a new chapter in my personal and professional life.”

Barnard has spent more than 20 years managing the medical research institute’s private investments portfolio consisting of global private equity, venture capital, real assets, and natural resources.

As managing director, he led a team of three directors and served as a member of the institute’s senior management team.

Previously, Barnard worked as an associate director at the Massachusetts Institute of Technology treasurer’s office for 10 years. There, he was responsible for managing real estate investments, according to his LinkedIn.

HHMI has named Greg DeNinno, current director of private investments, as Barnard’s successor. DeNinno has been with the institute since 2008 and focused on European private equity, venture, and small-cap buyouts.

The medical institute is also seeking an “experienced director” to add to the private investments team.

HHMI is led by “industry veteran”—and 2015 Power 100 member—Landis Zimmerman who previously headed up the University of Pennsylvania endowment.

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