Craig Thompson, chief executive of Memorial Sloan Kettering Cancer Center, resigned from the board of drugmaker Merck on Tuesday, after questions about the cancer center's ties to the pharmaceutical industry.
The New York Times previously reported Thompson's resignation from Merck and from lab services company Charles River Laboratories International.
The move follows the resignation of Sloan Kettering's chief medical officer, Jose Baselga, in September, after a New York Times and Pro Publica investigation revealed that he had not disclosed millions of dollars in payments from health-care companies in many of his research articles.
Baselga also resigned from the board of Bristol-Myers Squibb.
Merck said in a statement that Thompson's contributions on its board "demonstrate why it is so important to have leaders from the medical community represented."
The drug company said the size of its board will shrink to 12 directors after Thompson's resignation.
Memorial Sloan Kettering did not immediately comment on Thompson's stepping down from the boards. Charles River Laboratories could not be immediately reached for comment.