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). The gene discussed is KIF20A; the disease is esophageal squamous cell carcinoma.