Participants in the bottom quartiles of insulin-like growth factor-1 (IGF-I) and insulin-like growth factor-binding protein 3 (IGFBP-3) levels (median concentrations, 72 and 2,937 ng/mL, respectively) are at increased risk of ischemic stroke. The IGF axis may be involved in the pathogenesis of ischemic stroke. This evidence concerns the gene IGF1 and ischemic stroke.