LEPR and type 2 diabetes mellitus: We recently established a novel rat model of obese T2D, the Zucker fatty diabetes mellitus (ZFDM) rat harboring the fatty mutation (fa) in the leptin receptor gene. fa/fa male rats maintain the normoglycemic state until 7 weeks of age and then develop diabetes as early as 10 weeks of age, reaching 100% incidence at around 20 weeks of age [6].