Epic Systems, a healthcare database company that holds the medical records of hundreds of millions of Americans, is facing an antitrust investigation by the U.S. Federal Trade Commission, two sources familiar with the matter told Reuters.

The FTC has sent investigative demands to others in the health technology industry seeking information about how EPIC grants or withholds data access and interoperability, the sources said.

A spokesperson for the FTC declined to comment. A spokesperson for Epic did not immediately respond to a request for comment.