Therapeutic administration of topical ruxolitinib ameliorates established skin GVHD and protects HFSCs. (A-G) Lethally irradiated B6 mice were transplanted as in Figure 1. Recipient mice were treated with ruxolitinib ointment from day +10 after allogeneic SCT. Number of donor T cells (A), pathological skin GVHD scores (B) (n = 7-9 per group), and numbers of EGFP⁺ cells in 50 follicles on day +21 (C; n = 6 per group). (D-G) Ki-67 staining (D-E) and Annexin V assay (F-G) of donor T cells from the treated skin were performed on day +15 after allogeneic SCT (n = 8-9 per group). Data from 2 independent experiments were combined and shown as the mean ± SEM. The Mann-Whitney U test was used to compare the data (*P < .05; **P < .01; ***P < .005). ns, not significant; TCR, T-cell receptor.