Insulin--carcinogen or mitogen? Preclinical and clinical evidence from prostate, breast, pancreatic, and colorectal cancer research.

Diabetes mellitus is a chronic disease that affects > 23.6 million Americans, and occurs when the body is unable to produce or becomes resistant to endogenous insulin. This alteration of insulin's action reduces adequate utilization of glucose transporter type 4 (GLUT4) receptors, which are responsible for cellular glucose uptake.