For example, METTL1 has been shown to act as an oncogene in bladder cancer, hepatocellular carcinoma (HCC), acute myeloid leukemia, and intrahepatic cholangiocarcinoma [6,7,8,9,10]; the METTL3/14 complex acts as a tumor suppressor in thyroid and endometrial cancers [11,12,13]. The gene discussed is METTL1; the disease is hepatocellular carcinoma.