The Spontaneously Diabetic Torii (SDT) fatty rat is a novel animal model of type 2 diabetes, which was established by introducing the fa allele of the leptin receptor gene of the Zucker fatty rat into the genome of the SDT rat, a former animal model of non-obese type 2 diabetes found in an inbred strain of Sprague-Dawley (SD) rat [9, 10]. The gene discussed is LEPR; the disease is type 2 diabetes mellitus.