However, The Cancer Genome Atlas (TCGA) database indicates that compared with the expression levels of RNA and protein in normal tissues, the expression levels of CDCA5 in tumor tissues are significantly different; for example, CDCA5 expression is positive in more than 70% of non-small cell lung cancer [10], CDCA5 expression is high in urothelial carcinoma, oral squamous cell carcinoma, prostate cancer, and gastric cancer, and patients have poor prognosis [11]. This evidence concerns the gene CDCA5 and gastric cancer.