Nevertheless, long-term inbreeding and the establishment of a congenic line of rats carrying a frame-shift mutation of the GTPase immune-associated nucleotide-binding protein 5 (Gimap5) gene (BB DR.Gimap5−/−, hereafter referred to as Gimap5-DP where DP stands for Diabetes Prone) [13–15] have resulted in rats that no longer appear to develop beta-cell autoimmunity against insulin or GAD65 [16, 17] as previously described for outbred BB rats [18, 19]. This evidence concerns the gene INS and diabetes mellitus.