Perk deficiency in humans is the cause of the Wolcott-Rallison Syndrome characterized by permanent neonatal diabetes, exocrine pancreas deficiency, osteopenia, and growth retardation [9] and these defects are recapitulated in Perk KO mice [10], [11], [12]. The gene discussed is EIF2AK3; the disease is Wolcott-Rallison syndrome.