In the treatment of type 2 diabetes the following organs are considered main targets: (1) the pancreas and the skeletal muscle, for the improvement of beta cell function and peripheral insulin sensitivity; (2) the adipose tissue, to reduce obesity and lipotoxicity; (3) the gut, since it secretes incretin hormones; and (4) the kidney, heart, endothelium, brain and eye, to prevent or reduce the micro- and macrovascular complications associated with type 2 diabetes. The gene discussed is GIP; the disease is type 2 diabetes mellitus.