Of 51 patients with KRAS G12C–mutant advanced NSCLC, a partial response rate was 45% (23/51) and 51% had stable disease (26/51). The objective response rate in patients with LKB1 co-mutations was 64% (9/14). Patients with LKB1 co-mutations showed increase of CD4 and CD8 expression after treatment, indicating a potential immune response to therapy. This evidence concerns the gene CD8A and non-small cell lung carcinoma.