PDCD1 and neoplasm: To investigate the relationship between CXCR2P1 and tumor immune evasion by PD-1/PD-L1 signaling pathway, we first analyzed the correlation between the expression of CXCR2P1 and CD274. Results showed that CXCR2P1 was highly correlated with the expression of CD274 (ρSpearman = 0.60, p = 1.28 x 10-5, shown as Figure 5B) in tumor tissue.