Abstract:Key Points• We report that ruxolitinib reduces murine GVHD via increased Treg numbers.• We demonstrate the potent activity of ruxolitinib treatment in patients with corticosteroidrefractory GVHD.Graft-versus-host-disease (GVHD) is a severe complication of allogeneic hematopoietic cell transplantation (allo-HCT) characterized by the production of high levels of proinflammatory cytokines. Activated Janus kinases (JAKs) are required for T-effector cell responses in different inflammatory diseases, and their block… Show more