IGF1, also named as IBP1, MGF, IGF-IA and Somatomedin-C, belongs to the insulin family. IGF1 is structurally and functionally related to insulin but have a much higher growth-promoting activity. Altered expression or mutation of IGF-1 is associated with several human disorders, including type I diabetes and various forms of cancer. Defects in IGF1 are the cause of insulin-like growth factor I deficiency (IGF1 deficiency) which is an autosomal recessive disorder characterized by growth retardation, sensorineural deafness and mental retardation. The ; is specific to isoform IGF-1A.