Stephen Caldwell, MD, is a hepatologist specializing in a nonalcoholic steatohepatitis (NASH), including its relationship to so-called cryptogenic cirrhosis, ethnic and familial relationships and the role of mitochondrial dysfunction in the disease. He and his colleagues pioneered work on cellular ballooning and the role of small fat droplets in NASH and have also worked extensively with cyanoacrylates in the treatment of gastric variceal bleeding. He is overseeing a number of treatment trials for NASH and a variety of other liver diseases and is closely involved with a network of physicians and scientists working with coagulation disorders in liver disease.