Enables insulin-like growth factor I binding activity and insulin-like growth factor II binding activity. Acts upstream of or within negative regulation of cell population proliferation; regeneration; and response to hypoxia. Located in cytoplasm. Is expressed in several structures, including adaxial cell; brain; cardiovascular system; digestive system; and gonad. Human ortholog(s) of this gene implicated in diabetic angiopathy. Orthologous to human IGFBP1 (insulin like growth factor binding protein 1).