CD274 and meningioma: Immunological escape mechanisms in GBM and meningioma are characterized by low T‐cell infiltration and upregulation of PD‐L1 in tumor cells and peripheral macrophages.[7, 33, 34] To counter these mechanisms, we combined the nanoparticle therapy with systemic delivery of anti‐PD‐1 antibody, aiming to enhance immune cell infiltration and differentiation within the tumor microenvironment.