IGF1 and type 1 diabetes mellitus: Outside of T1D, rs689/rs3842753 is associated with insulin-like growth factor 1 levels (IGF-1) [79,80], paternally inherited IGF-2 levels at birth [81], age of diagnosis for T1D [82], starting insulin within one year of diagnosis [83], size at birth [84], hemoglobin A1c levels [79], blood glucose levels [79], and the age at which diabetes was diagnosed [83].