The transplantation of pancreatic islets and stem cell-derived insulin-producing cell clusters (SC-βs) into the portal vein of the liver has successfully restored glycemic regulation in patients with type 1 diabetes (T1D); however, the pool of eligible recipients of this procedure is limited, in part, because patients must endure chronic immunosuppression to prevent the immune destruction of the cells1. The gene discussed is INS; the disease is type 1 diabetes mellitus.