Importantly, it has been demonstrated that SAMe levels must be tightly controlled, and dysregulation of its homeostasis through lack of its catabolism by glycine N-methyltrasferase (GNMT) leads to liver disease and hepatocellular carcinoma (HCC), process that may be compensated by other methyltransferase activities such as NAM-methyltransferase (NNMT) [34,35,36,37]. Here, NNMT is linked to hepatocellular carcinoma.