IDO1 and neoplasm: To ameliorate the immunosuppressive microenvironment of intractable tumor and further boost the efficacy of immunotherapy, we report an all-round mesoporous nanocarrier composed of an upconverting nanoparticle core and a large-pore mesoporous silica shell (UCMS) that is simultaneously loaded with photosensitizer molecules, the IDO-derived peptide vaccine AL-9, and PD-L1 inhibitor.