IGF-binding proteins prolong the half-life of the IGFs and have been shown to either inhibit or stimulate the growth promoting effects of the IGFs on cell culture. They alter the interaction of IGFs with their cell surface receptors. Promotes anterior neural development by stimulating insulin growth factor (IGF) signaling via IGF receptors. Expressed both maternally and zygotically. Expressed on the dorsal side during gastrulation. Becomes confined to the floor plate, notochord and dorsal endoderm during neurulation. Expressed in additional domains at the tailbud stage in cranial nerves, ear vesicle, dorsal fin and somites. Dorsal midline expression becomes restricted to the floor plate and hypochord.