Imagine a room full of marvelous machines, each of which has an ignition switch to start it. But without the keys, there’s no way to activate the gizmos to find out what they do. In the body, molecular switches called receptors are activated by “keys,” called ligands. David Mangelsdorf, PhD, Chair of Pharmacology, studies “orphan receptors” – molecules that have no known key. He has identified the ligands to several orphan receptors, opening the door to developing drugs that could fight conditions as varied as cardiovascular disease and hookworm infection.