HGF and diabetes mellitus: Transplantation of human islets together with human bone marrow-derived mesenchymal stem cells (hBMSCs) overexpressing human HGF and human IL-1Ra under the kidney capsule of streptozotocin-induced diabetic non-obese diabetic/severe combined immunodeficient (NOD-SCID) reversed diabetes and reduced the number of islets required to achieving normoglycemia.