Somatic mutations in HCC tumors have also been observed in other cell cycle genes, including the tumor suppressor genes RB1 (~3–10%) (Kan et al., 2013; Ahn et al., 2014; Totoki et al., 2014; Yao S. et al., 2016) and CDKN2A (2~8%) (Guichard et al., 2012; Ahn et al., 2014; Totoki et al., 2014; Schulze et al., 2015; Kawai-Kitahata et al., 2016). Here, RB1 is linked to hepatocellular carcinoma.