Secretion of CXCL13 by the tumor infiltrating lymphocytes expressing high PD-1 levels serves to attract other immune cell subsets to the tumor microenvironment, including TFH cells and B-cells, and, strikingly, it strongly predicts response to anti-PD-1 therapy that correlates with increased overall survival and durable responses. The gene discussed is CXCL13; the disease is neoplasm.