HNF4A and liver cancer: The regulation of these sulfur amino acid (SAA) enzymes by HNF4α in liver cancer has drawn attention, with the intriguing observation that HNF4α, typically a tumor suppressor, may adopt a pro-tumor stance by inhibiting erastin-induced ferroptosis when its equilibrium is offset by hypermethylated in cancer 1 (HIC1) [37, 38].