TNFRSF4 and neoplasm: Therefore, its anti-tumor potential might derive from its ability to trigger an efficient Treg cells depletion thanks to the high levels of OX-40 on Treg cells (33, 38, 39), its ability to bind with high affinity to Treg and the recruitment of the activating FcγRs on NK cells by its Fc (32), similarly to the mechanism of action observed in a previous study involving a different anti-OX-40 monoclonal antibody (40).