CALR and neoplasm: designed a fibrin hydrogel as a therapeutic scaffold to co‐deliver cyclophosphamide (CTX) and anti‐PD‐L1 antibody (aPDL1) to regulate TME.[89] CTX can not only induce immunogenic apoptosis of tumor cells by calreticulin upregulation but also strengthen the anti‐tumor effect of cytotoxic T lymphocytes by limiting the frequency of Tregs in TME.