Pioglitazone, a thiazolidinedione approved for the treatment of diabetes, is a synthetic ligand for Peroxisome proliferator-activated receptor γ (PPARγ) and to a lesser extent PPARα [28]. PPARγ trans-activates PGC-1α thereby activating mitochondrial biogenesis in human subcutaneous tissue [29]. The gene discussed is PPARG; the disease is diabetes mellitus.