Cell replacement therapy such as intrahepatic transplantation of donor islets is relatively successful for type 1 diabetes in some patients. However, there are a number of limitations including immediate blood-mediated inflammatory response, potential risks of thrombosis and localized steatosis, and inability to retrieve or replace failed cells. Subcutaneous site is less invasive and easier-to-access but lacks sufficient vasculature to support the islet function. Dr. Minglin Ma and his collaborators reported a pre-vascularized islet construct that functioned in the subcutaneous site and corrected diabetes in mice for 3 months. (https://doi.org/10.1038/s41467-019-12373-5)