We compared the expression of the 15 immune gene cancer tissues and adjacent tissues in the TCGA-BLCA cohort (Figure 5A) and found that the expression of the CCR9, IL7, PTGER4, IL10, CTSG, and ZBTB16 proteins in the adjacent tissues was significantly higher than that in the cancerous tissues (P < 0.05). This evidence concerns the gene PTGER4 and cancer.