The DEGs Slc27a1, Cpt1a, Srebf1, and Foxo1 were enriched in insulin resistance pathway and also appeared in the network of top 10 upregulated and downregulated mRNAs, indicating these four mRNAs might play key roles in the development of hyperglycemia and T2D in GK rats at the age of 3 and 4 weeks. The gene discussed is FOXO1; the disease is Insulin resistance.