CD274 and neoplasm: This comprehensive approach synergistically amplifies the antitumor immune response by degrading the ECM to promote nanoparticle accumulation and immune cell infiltration, triggering ICD through NIR‐II PTT and GT to enhance tumor immunogenicity, and blocking PD‐L1 immunosuppression using PD‐L1 inhibitors, resulting in a significant inhibition of tumor growth and suppression of liver and lung metastasis in mouse models with subcutaneous bilateral 4T1 tumors.