It is clear that in the top ten genes in PPI network of CESC, ESCC, and LUSC, nine of them (BUB1, BUB1B, CCNA2, CCNB1, CCNB2, CDC20, CDC6, CDK1, and MAD2L1) are the same. This evidence concerns the gene CCNB2 and esophageal squamous cell carcinoma.