CPT demonstrated striking inhibition of both HIF-1α and HIF-2α accumulation in von Hippel–Lindau (VHL)-defective ccRCC cells, but surprisingly failed to inhibit protein levels of HIF-2α-dependent target genes (VEGF, PAI-1, ET-1, cyclin D1). Here, EPAS1 is linked to nonpapillary renal cell carcinoma.