Objective To evaluate the clinical efficacy and safety of umbilical cord-derived mesenchymal stem cell(MSC) treatment of refractory chronic graft-versus-host disease(cGVHD) after allogene hematopoietic stem cell transplantation. Methods Seven patients developed with c GVHD following allogene hematopoietic stem cell transplantation. Conventional immunosuppressive agent treatment yielded no efficacy. Based upon immunosuppressive agent therapy,umbilical cord-derived MSC treatment was supplemented with a cell d...