Insulin-like growth factor II(IGF-2) is the protein hormones which belongs to the family of insulin-like growth factors that share structural similarity to insulin. It is secreted by the liver and circulates in the blood. In fetal, IGF-2 is a major growth factor that regulating fetoplacental development influenced by placental lactogen. It is also involed in tissue differentiation. In adults, IGF-2 is involved in glucose metabolism in liver, adipose tissue and skeletal muscle. It is an imprinted gene, expressed only from the paternal allele. Loss of imprinting is associated with Beckwith-Wiedemann syndrome.