In a murine breast cancer model, the combined treatment of GPI‐anchored sEV‐PH20 hyaluronidase together with an anti‐PD‐L1 antibody had a more potent tumor suppressive effect than either monotherapy arguing that engineered Exo‐PH20 could serve as a potential agent for immunological cold tumors [172]. Here, CD274 is linked to breast carcinoma.