CD274 and neoplasm: CMTM6 is widely expressed on the plasma membrane of various tumor cells and induces PD-L1 post-translational modification by binding it on the plasma membrane as well as recycling endosomes to remain expressed in the cell surface through the protection against lysosomal-mediated degradation.37 Depletion of CMTM6 in tumor cells reduces the half-life of PD-L1 protein and relieves T-cell immunosuppression.