These observations led to the identification of a novel form of diabetes that involves the brain and has biochemical and molecular characteristics that overlap those of T2DM, such as an impaired function of several components of the insulin signalling pathway and gene coding for insulin-like growth factor 1 (IGF1) and 2 (IGF2) and their receptors [3], and has been named type 3 diabetes (T3DM) [1]. This evidence concerns the gene IGF1 and diabetes mellitus.