FCGR2A and neoplasm: Once Ipilimumab is administered, there are two main possibilities: (i) CD8+ cell proliferation would take place in lymphoid organs, and higher numbers of CD8+ cells with increased motility would migrate into tumors; (ii) Ipilimumab would mediate the ADCC of Treg cells through the FcγR of residing macrophages and/or NK cells; CD8+ cells would be relieved from Treg cell downregulation, and would kill tumor cells.