In connection with these observations, it is relevant that hypoxia induced HIF-1α stabilization is also known to cause increased expression of the MDR-1 and MRP-1 multidrug resistance proteins in cancer cells [78,79,80] and that hypoxia-induced increases in A549/cisplatin drug resistant cells are reversed by RNA interference of HIF-1α expression [81] or by silencing PGC-1α [76]. This evidence concerns the gene HIF1A and cancer.