3) Cell death causes the inflammatory microenvironment of tumor, promoting lymphocyte infiltration,[32] but also up‐regulates the immunosuppressive cells (e.g., M2 TAMs) [6, 27] and receptors (PD‐L1),[36] leading to the tumor immunosuppressive microenvironment.[6] Engineered M1Exos could polarize M2 TAMs into M1 phenotypes, and the anti‐PD‐L1 nanobody expressed on the outer membrane of engineered M1Exos could relieve the immunosuppression of T cells, ultimately leading to the remodeling of the tumor immune microenvironment and the improvement of radiotherapeutic efficacy. The gene discussed is CD274; the disease is neoplasm.