FCGR2A and neoplasm: Now that mouse models in which not only the murine FcγR genes have been exchanged with human counterparts [110,111] but also the murine μ region of heavy chain and kappa regions of Ig light chain genes have been exchanged with human IgG constant heavy regions and human κ light region genes, respectively [112], are available, FcγRs-specific IgG antibodies can be developed to indicate the contribution of FcγR to long-term anti-tumor efficacy using these mouse models.