CSF3 and graft versus host disease: Second, treating healthy donors with G-CSF decreases the production of tumor necrosis factor alpha, IL-2, and interferon-γ; the immunoregulatory effects of G-CSF on cytokines, T cells, and regulatory cells of donors might contribute to the lower incidence of GVHD after using G-CSF-primed bone marrow harvests and/or G-CSF-mobilized peripheral blood harvests as allografts (39, 46).