ABCB4 and hepatocellular carcinoma: To explore whether SAM supplementation as a food additive could have a chemopreventive effect at the late precancerous stage of inflammation-mediated HCC development, we supplemented 11-month-old Mdr2-KO mice with either SAM or saline by gavage during either 17 (short-term treatment) or 51 (long-term treatment) days.