For example, analyzing a cohort of 70 lung cancer patients treated with anti-PD-1 or anti-PD-L1 antibodies after progression to platinum-based chemotherapy, Arasanz and co-coworkers performed an immunophenotyping on peripheral blood samples collected at baseline and after the second cycle of treatment, focusing their attention on CD4+ lymphocytes. Here, PDCD1 is linked to lung cancer.