His major research interests include two major clinic areas: the treatment of sarcoidosis and the diagnosis of pneumonia. Along with his long time collaborator Dr. Elyse Lower, he has developed several novel treatments for sarcoidosis, including methotrexate, thalidomide, leflunomide, and infliximab. Current studies include treatments for sarcoidosis associated fatigue and pulmonary hypertension due to sarcoidosis.