PPARα regulates tumor progression, foe or friend?

PPARα belongs to the peroxisome-proliferator-activated receptors (PPARs) family that consists of PPARα, PPARδ, and PAPRγ. Activation of PPARα by ligands including fatty acids and their derivatives as well as some synthetic compounds regulates tumor progression in various tissues. Activated PPARα inhibits or promotes tumorigenesis depending on the specific tissues, but the molecular mechanism is still unclear. In this review, the recent progress of PPARα regulating tumorigenesis is discussed.