In the present study, insulin-stimulated IRS-1 and AKT phosphorylation in skeletal muscle were significantly blunted in CUG-SGA rats, which is consistent with a previous report [16], and suggests that impairment of the IRS-1-PI3K-AKT signaling pathway may contribute to the insulin resistance observed in the CUG-SGA rats. The gene discussed is IRS1; the disease is Insulin resistance.