These findings offer novel insights into the tumor-immunosuppression mechanism and provide the rationale for applying exosomal PD-L1 as an effective biomarker for immunotherapy as a complement to tissue biopsy, with the advantages of its non-invasive nature, accurate representation and real-time monitoring, although more basic studies and long-term clinical trials are needed to further confirm the detailed action mechanisms of PD-L1-positive extracellular vesicles and their clinical impact. This evidence concerns the gene CD274 and neoplasm.