Previous work demonstrated that the formation of a “ring of TGF-β1” around pancreatic islets may protect the newly regenerated islet β cells against infiltrating lymphocytes and macrophages [23], providing a safe environment for promotion of regeneration of pancreatic islet β cells in long-standing type 1 diabetic patients [20,24]. This evidence concerns the gene TGFB1 and type 1 diabetes mellitus.