CD4 and metastatic malignant neoplasm in the lymph nodes: The frequency of circulating peripheral blood terminally differentiated effector memory CD8+ cells (r = − 0.86, p = 0.01) and CD4+ cells (r = − 0.85, p = 0.03) negatively correlated with lymph node metastasis in the treatment-naïve setting (Fig. 6B).