LEPR and Hypoinsulinemia: In the past, several QTL have been identified in the mid-region of mouse chromosome 4 in the proximity of the leptin receptor gene (Lepr) relating to hyperglycemia and hypoinsulinemia (Leiter et al., 1998; Plum et al., 2002; Scherneck et al., 2009; Davis et al., 2012; Kluge et al., 2012).