CD8A and lung adenocarcinoma: Evidence by previous studies had been showed changes in a white blood count and platelet in cancer patients associated with the disease severity and survival.[4–6] Lymphocytes also played critical roles in promoting systemic immune responses against tumors, and lymphocytopenia is associated with poor outcomes in many malignancies.[7,8] High expression of CD8+ T lymphocytes, which predicts a favorable prognosis in lung adenocarcinoma was reported.[9] Platelet played another important role in cancer prognosis, too.