The FG network revealed linking nodes (that are not among the association signals) with known links to glucose homeostasis and diabetes, such asGCK (encoding the beta cell glucose sensor glucokinase),GCG (encoding the peptide hormone glucagon secreted by the alpha cells of the pancreas) andGIP (encoding the incretin hormone gastric inhibitory polypeptide). The gene discussed is GCG; the disease is diabetes mellitus.