Additionally, pharmacologicalPPARγ agonists, including pioglitazone (3), areassociated with an increased risk of bladder cancer.7−9 Pharmacological antagonism of PPARγ in vitro has been shown to lead to antiproliferative effects in PPARγ-activatedcancer cell lines3 and to promote osteogenesis,10 and genetic experiments suggest that PPARγinverse agonists may induce proinflammatory effects in the tumor environment.4 This evidence concerns the gene PPARG and urinary bladder carcinoma.