The results of 23 studies revealed that patients with KRAS-mutant NSCLC were much more expected to be PD-L1 positive than patients with KRAS wild-type tumors (odd ratio = 1.87; 95% CI, (1.34, 2.61); p = 0.0002), indicating a significant positive association between PD-L1 expression and KRAS mutation status [38]. This evidence concerns the gene KRAS and non-small cell lung carcinoma.