More importantly, it is apparent that fenofibrate, a PPAR alpha (PPAR-α)-specific agonist, further represses the expression of hypoxia-induced HIF-1α and CA9 in tumors by activating the AMP-activated protein kinase (AMPK) pathway and SIRT1 in tumor cells using HO-1.75 This evidence concerns the gene CA9 and neoplasm.