BKS.Cg-Dock7m + / + Leprdb/J mice (herein called db/db mice), which are genetically deficient in the leptin receptor and spontaneously develop insulin resistance, diabetes and morbid obesity, represent the gold-standard model for type 2 diabetes mellitus (DM2) and are extensively used to study diabetes complications (Sullivan et al., 2004). The gene discussed is LEPR; the disease is diabetes mellitus.