CD8A and lung adenocarcinoma: Because lymphocytes are critical in promoting systemic immune responses against tumors, lymphocytopenia is associated with poor outcomes in many solid cancers.[7,8] Cytotoxic T lymphocytes elicit adaptive cellular immunity against tumor cells,[28] and Ye et al found that high expression of CD8+ T lymphocytes predicts better prognosis in patients with lung adenocarcinoma.[9] In our study, patients with a lymphocyte percentage of >20.8% had a better prognosis than did other patients.