PPARγ agonists inhibit the proliferative activity of neoplastic cells, suppress the growth of human tumor xenografts in nude mice [31, 32] and reduce the frequency of spontaneous and carcinogen induced pre-neoplastic and neoplastic lesions in animals [31, 33], which is indicative of the tumor suppressor effects of PPARγ [31]. This evidence concerns the gene PPARG and neoplasm.