CYM reduces the number of macrophages in the aGVHD target organs without directly affecting their proliferation. (a–c) Both percent and number of macrophages were analyzed in the spleen, liver, lung and intestine after CYM treatment day 4 post BMT. CD11b+F4/80+ cells were identified as macrophages. (d, e) The proliferation of macrophages was analyzed by an in vivo EdU assay, and both the percentage and number of EdU+ macrophages were not affected by CYM treatment. (f, g) The percent and number of transferred CFSE-labeled macrophages were analyzed in the spleen, liver, lung and intestine after CYM treatment day 4 post BMT. The data are representative of three independent experiments, each using 4–5 mice per group. Data are shown as the mean±s.e.m. (*P<0.05, ***P<0.005). BMT, bone marrow transplantation; aGVHD, acute graft-versus-host disease.