Insulin-like growth factor binding protein-2 (IGFBP-2) is one of six characterized IGFBPs which specifically bind and modulate the actions of IGF-I and IGF-II. The binding affinity of IGFBP-2 for IGF-II is estimated to be significantly higher than for IGF-I, suggesting a role in regulation of IGF-II action. Studies in the fetal sheep indicate that IGFBP-2 is produced in many tissues, apparently coincident with IGF-II expression.

Recent studies of serum IGFBP-2 levels have shown that, unlike for IGFBP-1, there is negligible variability during the day and, unlike IGFBP-1 and IGFBP-3, virtually no change during puberty. IGFBP-2 has also been identified in other body fluids such as cerebrospinal, amniotic and coelomic fluids, urine and seminal fluid.