By analyzing the baseline and early-treatment peripheral blood lymphocyte profiles in patients with advanced lung cancer receiving chemotherapy alone or in combination with immunotherapy, one key finding was that distinct subsets at baseline, including CD3-CD16+CD56+ cells, CD3-CD19+ cells, and an increased CD4+/CD8+ T cell ratio, were more frequently associated with favorable responses. The gene discussed is CD4; the disease is lung carcinoma.