RXRA and cancer: A large body of evidence suggests that PPARγ functions as a tumor suppressor, as activation of the PPARγ/RXRα signaling pathway in different types of cancer, including colon (113), lung (114, 115), pancreatic (116), prostate (117), and breast (118, 119) cancers, leads to inhibition of cell growth, decreased tumor invasiveness, and reduced production of proinflammatory cytokines.