It can be expressed in various forms in tumor cells, such as cytoplasmic PD-L1 (cPD-L1), membrane PD-L1 (mPD-L1), soluble PD-L1 (sPD-L1), and extracellular vesicular PD-L1 (EV PD-L1) [141]. This evidence concerns the gene CD274 and neoplasm.