The insulin-like growth factors, isolated from plasma, are structurally and functionally related to insulin but have a much higher growth-promoting activity. Promotes anterior neural development (PubMed:11709186). Acts as a ligand for integrin which is required for IGF2 signaling (By similarity). Expressed both maternally and zygotically. Expressed in the dorsal midline during gastrulation and neurulation. Belongs to the insulin family.