C57BL/6N mice do not harbor the mutation of nicotinamide nucleotide transhydrogenase (NNT) ,which has been associated with impaired β-cell function and glucose intolerance in some studies (Aston-Mourney et al., 2007; Freeman et al., 2006; Toye et al., 2005). This evidence concerns the gene NNT and Glucose intolerance.