The nanopolymer also reprograms the tumor immune microenvironment by reducing PD-L1, IDO-1, and TGF-β and increasing CD8+ T cells, M1-like macrophages, which unleashes the potential of transforming the tumor from cold tumor to hot tumor, greatly inhibiting tumor growth, and improving the survival rate of bladder cancer mice (119). Here, IDO1 is linked to neoplasm.