MTOR and urinary bladder cancer: The involvement of the Akt-mTOR pathway as a downstream effector triggered by PD-L1 has also been reported in processes related to invasion and metastasis, such as the epithelial–mesenchymal transition (EMT) process in hypopharyngeal squamous-cell carcinoma (HSCC) [133], as well as in chemotherapy resistance in bladder cancers [116].