HIF1A and osteosarcoma: In osteosarcoma (OS) cells under hypoxic conditions, HIF-1α induces the overexpression of the mitochondrial NADH dehydrogenase (ubiquinone) 1 alpha subcomplex 4-like 2 (NDUFA4L2) protein, which in turn promoted OS cell migration, invasion, proliferation, and EMT.