Monoclonal antibody therapy is a form of passive immunization. Indeed, longer‐term vaccine‐like or vaccinal immunity has been demonstrated in anti‐CD20‐treated mice via FcγRIIa50, 51 and in vitro recall memory responses from CD20‐treated patients.52 Although this is dependent on FcγR and anti‐CD20, the mechanism by which long‐term anti‐tumor response is established remains unclear.