MAP2K1 and fetal growth restriction: Huang et al. also reported the role of miR-424 in the pathogenesis of IUGR by demonstrating that miR-424 is significantly increased and its target genes, mitogen-activated protein kinase 1 (MEK1) and fibroblast growth factor receptor 1 (FGFR1), are significantly reduced in placentas from IUGR pregnancies [117].