Moreover, T cells from donors treated with G-CSF have a reduced capacity to induce GvHD [12] and show a diminished proliferative response of T cells to allogeneic and mitogenic stimulation [16] probably resulting from the induction of Tr1-like regulatory T cells producing high amounts of IL10 and to a lesser extent TGF-β [17]. The gene discussed is CSF3; the disease is graft versus host disease.