KRT18 and fetal growth restriction: On Day 28, the DEGs specific to female IUGR piglets were functionally associated with GO terms, including a response to a toxic substance (CBL, HP, and FOS), cold-induced thermogenesis (ADRB1, NPR3, and PEMT), epithelial cell apoptotic process (ANGPT1, CCL2, KRT18, and KRT8), as well as phosphatidylinositol 3-kinase signaling (ANGPT1, IER3, and PRR5) (Fig. 6g).