CD274 and neoplasm: Consequently, the produced Mn2+ enabled a tumor‐specific MR imaging, the hypoxia alleviation down‐regulated the expression of immunosuppressive PD‐L1, and the binding of released IPI549 to PI3Kγ on MDSC resulted in the M1‐polarization of TAMs and activation of tumor‐suppressive T‐lymphocytes.