HIF1A and hepatocellular carcinoma: Mitophagy, a specific form of autophagy, is activated under hypoxic conditions in HCC cells by the upregulation of the mitophagy targets of HIF-1α, B-cell lymphoma-2/adenovirus E1B 19 kDa-interacting protein 3 (BNIP3) and BNIP3-like protein X (NIX).