Insulin-like growth factors (IGFs) I and II are proinsulin-like peptides. IGF I is produced in adult and embryonic kidney. It is likely that IGF I produced locally in adult kidney regulates processes of renal transport, metabolism and growth. Renal IGF I production is stimulated by growth hormone (GH) and by epidermal growth factor (EGF). The identity of additional factors that regulate IGF I gene expression in settings such as compensatory hypertrophy and diabetes mellitus is unknown. IGF I and IGF II produced in embryonic kidney promote the metanephrogenic process. The identity of factors that regulate metanephric IGF gene expression is yet to be determined.