Studies have shown that intrauterine growth restriction due to malnutrition during pregnancy is significantly associated with placental wnt family member 2 (Wnt2) hypomethylation [58], and the change of liver insulin-like growth factor 2 (IGF2) hypomethylation mediates liver dysplasia due to pregnant low protein diet [59]. The gene discussed is IGF2; the disease is fetal growth restriction.