IDO1 and prostate carcinoma: As shown in our previous study, N-cadherin mediates prostate cancer invasion and metastasis by activating EMT,19 and some researchers have shown a link between EMT and immunosuppression and an increase in the expression of immunosuppression checkpoints.14–18 Therefore, we performed immunohistochemistry (IHC) staining of tissue microarrays (TMAs) containing human prostate cancer samples of different stages using antibodies against N-cadherin and PD-L1/IDO-1 to determine the effect of N-cadherin on the expression of immunosuppressive factors in prostate cancer.