However, after PDAC is converted from a noninflamed tumor to an inflamed one like melanoma as the result of an agent that induces effector T cell infiltration, further combining the anti-PD-1/PD-L1 antibody treatment with IDO inhibitor with the anti-PD-1/PD-L1 antibody treatment would not result in additional antitumor activity in the preclinical model of PDAC. The gene discussed is IDO1; the disease is neoplasm.