IDO1 and neoplasm: To address this, a multifunctional nanoparticle, TPI@RPB, was constructed with RGD-PEG-BSA as the carrier for tumor-targeted delivery, while co-loading the self-synthesized endoplasmic reticulum (ER) target photosensitizer TSE-Ppa and Indoleamine 2,3-dioxygenase 1 (IDO-1) inhibitor 1-MT.