To potentiate the tumor for checkpoint immunotherapy, chemotherapy has been applied to induce immunogenic cell death (ICD) to enhance tumor immunogenicity1; whereas, targeted therapy that modulates immune activation signaling (e.g., toll-like receptor5 and stimulator of interferon gene signaling6) or immunosuppressive pathways (e.g., indoleamine 2,3-dioxygenase (IDO)7, macrophage-colony-stimulating factor (M-CSF) regulatory pathway8, etc.)has been used to reprogram immunosuppressive TME9. The gene discussed is IDO2; the disease is neoplasm.