Low-dose cyclophosphamide has been shown to deplete Treg cells by inhibiting their proliferation and inducing apoptosis, and to attenuate their function by suppressing the expression of FOXP3 and GITR.824 In addition, TKIs (sunitinib, sorafenib, and imatinib) have been reported to prevent the expansion and function of intratumoral Treg cells.825–827 Although these approaches have been shown to inhibit the proliferation and function of Treg cells, they are not specific to tumor-infiltrating Treg cells. The gene discussed is TNFRSF18; the disease is neoplasm.