In the presence of functional immune cells, more than 70% of donor hepatocytes are cleared within 2–24 hours after transplantation, limiting their survival and integration into the liver parenchyma.57 Furthermore, the recipient Fah−/−, Rag2−/−, and Il2rg−/− mice on the NOD-strain background mice used in Zabulica et al56 do not represent a mouse model of ornithine transcarbamylase deficiency; therefore, the study did not demonstrate correction of the disease phenotype in the host. Here, RAG2 is linked to hyperinsulinemic hypoglycemia, familial, 4.