We believed that the heterogeneity is derived from the multiple intervention modalities (combinational therapies and PD-1/PD-L1 inhibitors) and various tumor types (NSCLC, melanoma, sarcoma, and others); therefore, although we performed subgroup analyses to mitigate that limitation, high heterogeneity should be noted when interpreting our results. This evidence concerns the gene PDCD1 and non-small cell lung carcinoma.