We investigated the chemopreventive potential of S-adenosylmethionine (SAM), an essential donor for all methylation reactions in the cell, at the late precancerous stage of HCC development using the Mdr2-knockout (Mdr2-KO, Abcb4−/−) mice, a model of inflammation-mediated hepatocarcinogenesis. The gene discussed is ABCB4; the disease is hepatocellular carcinoma.