CD274 and colorectal carcinoma: The possible reasons could be that (1) the binding between a PD-1 inhibitor and PD-L1 could promote antitumor immunity and inhibit immune escape, which may suppress CRC tumor growth (27); (2) apatinib may synergize the antitumor effects of a PD-1 inhibitor (28), thus indicating that PD-1 plus apatinib had potentially better treatment efficacy than apatinib monotherapy; and (3) the sample size of this study was relatively small, which resulted in low statistical power, which indicated no statistical significance was observed in the treatment response between groups.