HIF1A and colonic neoplasm: HIF-2α depletion downregulated the expression of heme oxygenase (HMOX1) genes that exert antioxidant functions in RCC.73 In colon cancer cells, absence of oncogenic KRAS or both HIF-1α and HIF-2α led to decreased cardiolipin level and inefficient mitochondrial respiration; ACSL5 induction is directly responsible for maintaining cardiolipin level and efficient mitochondrial respiration in cancer.