In addition, antibodies directly activate the complement pathway to enable killing of antibody-coated tumor cells via complement-dependent cytotoxicity (CDC).346,347 The four subtypes of IgG bind different types of FcR with different binding capabilities and different effector functions in ADCC and ADCP, and the IgG subclass must be taken into consideration during antitumor therapeutic antibody selection.348–350 Since most CD47 antibodies preferentially bind to RBCs, if IgG1 is selected, immune cells such as NK cells and macrophages will be activated by RBCs. Here, CD47 is linked to neoplasm.