To reconcile our data with previous reports attributing a critical role to NK cells in the context of PD-L1/PD-1 immune checkpoint blockade and to account for the findings observed in a set of patients who responded to PD-L1/PD-1 blockade therapy despite bearing a PD-L1-negative tumor, two hypotheses have been put forward (62). The gene discussed is CD274; the disease is neoplasm.