Tofacitinib effectively reverses graft-versus-host disease (GVHD)-like disease. (a) Curves show the percentage of initial weight in mice treated with vehicle control, or oral tofacitinib at 12.5, or 50 mg kg–1 BID starting 4 days after OT-I cell transfer (arrow), the time of onset of GVHD-like disease. (b) Individual clinical scores of the mice 14 days after OT-I cell transfer are plotted. The bars are mean scores of each group. *P<0.05, U-test. (c–g) Clinical and histologic photographs of mice treated with vehicle control (c, d), or with tofacitinib daily (starting on day 4 after OT-I cell transfer) at 12.5 (e, f), or 50 mg kg–1 BID (g, h) 14 days after OT-I cell transfer, and those of untreated mice (i, j). OT-I cells, transgenic T cells. Bar=50 μm.