CD274 and neoplasm: CS‐I/J@CM NPs greatly boosted the antitumor immune response by remodeling the tumor immunosuppressive microenvironment (TIME) of glioblastoma through various mechanisms, including hypoxia alleviation‐induced TAM repolarization, IND‐mediated inhibition of Treg cells, and JQ1‐restricted PD‐L1 expression.