MAPK3 and hepatocellular carcinoma: One week after HDTV injection, we treated all mice with tamoxifen for 5 days, and we observed strikingly exacerbated HCC in Lifrfl/fl;Cre-ERT2 mice compared with Lifrfl/fl mice (Fig. 1n–q), suggesting that Lifr is a suppressor of oncogene-induced HCC in adults.