Studies in PERK-null mice and in the human disease Wolcott-Rallison syndrome, a rare infantile-onset insulin-requiring diabetes caused by a loss-of-function mutation in the PERK gene, revealed the involvement of UPR and more specifically, the PERK-eIF2α pathway (Delépine et al. 2000, Zhang, Feng et al. 2006). The gene discussed is EIF2A; the disease is Wolcott-Rallison syndrome.