Given the association between ER stress and glucose intolerance, as observed postnatally in former IUGR offspring, it appears logical that tissues of IUGR subjects display an Unfolded Protein Response (UPR) associated with ER stress in organs crucial to glucose homeostasis such as the liver and pancreas, as ER stress can impair insulin signaling and glucose metabolism through disruption of cellular protein folding and inflammatory pathways [109]. This evidence concerns the gene INS and fetal growth restriction.