Dr. Friedman's research on various aspects of obesity received national attention in late 1994, when it was announced that he and his colleagues had isolated the mouse ob gene and its human homologue. They subsequently found that injections of the encoded protein, leptin, decreases body weight of mice by reducing food intake and increasing energy expenditure. Current research on leptin is aimed at understanding the genetic basis of obesity in human and the neural mechanisms by which leptin transmits its weight reducing signal.