The results showed that the mRNA expression levels of hub genes (PBK, KIF2C, NUF2, KIF20A, RAD51AP1 and DEPDC1) in tumor samples (EAC, ESCC) were significantly higher than in normal samples (P < 0.05) (Fig. 6A). This evidence concerns the gene KIF2C and esophageal squamous cell carcinoma.