Bacterial outer membrane vesicles have robust immune adjuvant effects and can elicit high level antitumor immunity.[52] Meanwhile, extracellular vesicles have the advantage of easy genetic engineering, which can improve tumor microenvironment by displaying PD‐1 to block PD‐L1 on tumor cells.[53] In this study, PLGA is selected as the carrier material. The gene discussed is CD274; the disease is neoplasm.