CD4 and type 1 diabetes mellitus: Although the doses of Tregs infused were lower than what has been administered in type 1 diabetes,7 our highest dose was in the range of the number of Tregs contained within the cell product infused in the liver transplant trial from Japan (31‐466 × 106 CD4+ Foxp3+ T cells).11 The lack of signs of over‐immunosuppression is very reassuring, considering that the Tregs had been expanded under polyclonal conditions and were therefore potentially capable of exerting nonspecific suppressive effects.