Additionally, strong coexpression between both inhibitory receptors has been observed in tumor antigen-specific CD8+ T cells in the periphery and at tumor sites in patients with advanced melanoma [27], while in lung adenocarcinoma, this coexpression implies the existence of suppressive phenotypes of tumor-infiltrating lymphocytes, which is closely correlated with poor clinical outcomes [28]. This evidence concerns the gene CD8A and lung adenocarcinoma.