Given the observation that multiple factors can induce PD-L1 expression, it may be feasible to treat patients with these molecules (e.g., IFN-α, -β, and -γ 16; cisplatin 55) to induce PD-L1 expression in the tumor microenvironment and expand the population of patients who might benefit from treatment with PD-1-pathway–directed agents. Here, PDCD1 is linked to neoplasm.