Whereas circulating BCAAs and AAAs are increased, glycine, the simplest amino acid, is consistently reported to be lower in association with suppressed hepatic glycine biosynthetic genes (e.g., alanine-glyoxylate aminotransferase [AGXT] and serine hydroxymethyltransferase [SHMT]) and inversely associated with the risk or severity of NAFLD/NASH, CVD and related cardiometabolic diseases in both mouse models and patients (83, 192, 195, 196, 199, 201, 221–225). The gene discussed is AGXT; the disease is metabolic dysfunction-associated steatotic liver disease.