Pioglitazone (ACTOS®) is a member of a class of oral antidiabetic agents known as thiazolidinediones. The insulin-sensitizing actions of thiazolidinediones are at least partially mediated through the peroxisome proliferator-activated receptor gamma. These receptors are found primarily in adipocytes, vascular endothelial cells, monocytes, hepatocytes, and to a lesser extent myocytes.