found that IGF1 and IGF2 levels were significantly lower in islet autoantibody positive compared with islet autoantibody negative relatives of individuals with T1D, and that IGF1 levels decreased over time in subjects with multiple islet autoantibodies and in those who progressed to T1D, in parallel with decreasing β-cell function (79). This evidence concerns the gene IGF1 and type 1 diabetes mellitus.