We found that the qRT-PCR detection performed in both blood and tissue specimens was numerically but not statistically significant in accordance with IHC assay (corresponding to a p-value of 0.84 and 0.55, respectively), and PD-L1 expression level in blood could independently predict the efficacy of immunotherapy in patients with GC (p-value = 0.04). Here, CD274 is linked to gastric cancer.