KIF4A and esophageal squamous cell carcinoma: To further explore KIF4A expression between ESCC and paired adjacent normal tissues, quantitative real-time PCR (qRT-PCR) was used to confirm the mRNA levels of KIF4A, and the result showed that in 25 paired of tumor tissues, KIF4A mRNA levels were significantly higher than those in adjacent normal tissues (1.7 vs. 5.3-fold changes) (Figure 4A).