NNT and Glucose intolerance: C57BL/6J mice exhibit impaired insulin secretion and glucose intolerance, the C57BL/6J strain, but not the 129Sv or C57BL/6N strain, has a mutation in the nicotinamide nucleotide transhydrogenase (Nnt) gene, and the impaired insulin secretion and glucose intolerance are rescued by the transgenic expression of Nnt [66,67,68,69,70] (Mouse Genome Project: Sanger institute, https://www.sanger.ac.uk/data/mouse-genomes-project/).