Despite the clinical efficacy of immune checkpoint blockades (ICB) that target cytotoxic T-lymphocyte-associated protein 4 and programmed cell death 1 (PD-1)/PD-1 ligand 1 (PD-L1), only a fraction of patients achieve sustained responses as a result of the complex and heterogeneous tumor microenvironment (TME).9,10. The gene discussed is PDCD1; the disease is neoplasm.