RB1 and hepatocellular carcinoma: Loss of Rb is involved in initiation of cancers including retinoblastoma, HPV, small-cell lung carcinoma, and HCC (Meuwissen et al., 2003; Doorbar, 2006; Mayhew et al., 2007; Munakata et al., 2007; Dimaras et al., 2008).