Troglitazone is a TZD which was approved for the treatment of insulin resistance and hyperglycemia in Type II diabetes, under the trade name Resulin™, but was withdrawn from the market due to hepatotoxicity. Troglitazone is a potent and selective PPARγ agonist. The EC50 values for transactivation of human and mouse PPARγ in a cell-based assay are 0.55 and 0.78 µM, respectively. In the same assay system, no activation of PPARα and PPAR.delta. was observed at concentrations up to 10 µM. Troglitazone binds to the PPARγ ligand-binding domain (LBD) but fails to induce interaction of the PPARγ LBD with the transcriptional coactivators SRC-1, TIF2, AIB1, p300, or TRAP220. Troglitazone also induces cell cycle arrest and apoptosis in several cancer cell lines with an EC50 of 10 µM.