SREBF1 and breast cancer: HIF activation may also inhibit medium- and long-chain acyl-CoA dehydrogenases (MCADs and LCADs), as described in hepatocellular carcinoma [80]; may drive increased fatty acid synthesis via activation of Akt and sterol regulatory element binding protein-1 (SREBP-1), as described in breast cancer cells [81]; and may thus drive intracellular lipid accumulation via multiple pathways [78].