The use of the mIgG2a isotype backbone in PC-61, which interacts beside FcγRIIb and FcγRIII with activating FcγRI and FcγRIV [40], can overcome this inhibitory signaling of FcγRIIb and may license tumor-associated macrophages for Treg depletion. The gene discussed is FCGR2B; the disease is neoplasm.