In this context, Devedjian and colleagues showed that, when IGF2 overexpression is restricted to β-cells, mice developed hyperinsulinemia, hyperglycemia and impaired response to glucose tolerance tests, even though serum levels of IGF2 were only ~twofold higher than WT animals and comparable to the levels observed by us after IDS.IGF2co gene therapy (Devedjian et al, 2000). The gene discussed is IGF2; the disease is hyperinsulinism.