SIRPA and neoplasm: To overcome these challenges, Xie et al. designed a bioorthogonal reaction-based pH-responsive exosome (M1 Exo-Ab) to improve tumor immunotherapy.211 DBCO-modified anti-CD47 antibody (aCD47) and anti-signal regulatory protein alpha (SIRP) antibody (aSIRP) were bonded to M1 macrophage exosomes (M1 Exos) and a pH-sensitive benzoic imine bond.