Additionally, we estimated the expression of Ki67 (marker of proliferating cells) and regulators of cell cycle progression, including cell division cycle 42 (CDC42), cyclin A2 (CCNA2), cyclin B1 (CCNB1), cyclin D1 (CCND1), and cyclin E1 (CCNE1) in TCGA database, and found that all the genes except CCND1 were significantly upregulated in HCC tissues compared with normal controls (Supplementary Figure S4A). This evidence concerns the gene CCNA2 and hepatocellular carcinoma.