Together with the known facts that both SAM deficiency (in the Mat1a-KO mice) and its increased level (in the Gnmt-KO mice) cause HCC development [58, 64], our data demonstrate that a balanced hepatic SAM level and SAM:SAH ratio are necessary to maintain liver health and prevent HCC development in chronic liver injury. The gene discussed is GNMT; the disease is hepatocellular carcinoma.