The expression of 43 genes involved in the amylin, insulin and leptin signal transduction pathways (Table 1) were examined in four brain regions of L44 transgenic mice over different disease stages; T1, prediabetic (100 days); T2, diabetes onset (blood glucose >11 mM for three consecutive weekly measurements); and T3, post-diabetic (400 days). This evidence concerns the gene IAPP and diabetes mellitus.