IRS2 and gestational diabetes: The mechanisms by which GDM-affected women become less insulin and lipid sensitive are not well understood, but studies have shown that downstream insulin effectors, insulin receptor substrates 1 and 2 (IRS-1 and IRS-2) decrease in GDM, whereas P85, a subunit of phosphatidylinositol-3-kinase (PI3-K), is increased [70].