PPARD and colonic neoplasm: Given that PPARβ/δ expression is naturally high in the colon, gene mutations in PPARB/D occur with very low frequency in colon tumors, and expression levels of PPARB/D mRNA are not associated with colon cancer patient survival, it makes much more sense that natural agonists or antagonists function to maintain homeostasis in colon cells by promoting terminal differentiation or attenuating inflammation.