Marty Makary's resignation leaves the agency with temporary directors in three top positions, and a number of newly instituted policies with an unclear future.

Makary’s exit ends a turbulent run marred by leadership upheaval, mass layoffs, political pressure and public spats with drugmakers.

Food and Drug Administration Commissioner Marty Makary is resigning from his role after a tumultuous tenure.

What Marty Makary's successor can learn from his mistakes.