Multifunctional protein that plays a critical role in regulating the availability of IGFs such as IGF1 and IGF2 to their receptors and thereby regulates IGF-mediated cellular processes including cell migration, proliferation, differentiation or apoptosis in a cell-type specific manner (PubMed:11397844, PubMed:15972819). Also plays a positive role in cell migration by interacting with integrin ITGA5:ITGB1 through its RGD motif (PubMed:7504269). Mechanistically, binding to integrins leads to activation of focal adhesion kinase/PTK2 and stimulation of the mitogen-activated protein kinase (MAPK) pathway (PubMed:11397844). Regulates cardiomyocyte apoptosis by suppressing HIF-1alpha/HIF1A ubiquitination and subsequent degradation (By similarity). {ECO:0000250|UniProtKB:P21743, ECO:0000269|PubMed:11397844, ECO:0000269|PubMed:15972819, ECO:0000269|PubMed:3419931, ECO:0000269|PubMed:7504269}. This is the function of ENSG00000146678 (IGFBP1, insulin like growth factor binding protein 1).