Though numerous studies have shown that lung cancer patients have lower levels of CD4+ T cells, CD4+/CD8+ ratio, NK cell levels, and a higher regulatory T cells (Tregs) levels as compared to the healthy population [10, 11], the prognostic value of peripheral blood lymphocyte subsets in predicting immunotherapy efficacy in advanced NSCLC patients has not been demonstrated. This evidence concerns the gene CD8A and non-small cell lung carcinoma.