As a basic scientist with an interest in defects in the immune system, Dr. Verbsky has actively investigated and defined the genetic causes of patients with severe immune defects. He described a novel autoinflammatory disease due to deficiency in the IL-1 receptor antagonist gene. Recently, together with Drs. Dimmock, Jacob, Mayer, and Worthey, they have described a novel presentation of X-linked lymphoproliferative disease due to a new mutation in XIAP. Studying patients with these rare defects will teach us about the mechanisms of autoimmunity.