Involved in endochondral bone formation as negative regulator of bone mineralization. Stimulates the proliferation of endothelial cells and promotes angiogenesis. Inhibits MMP9 proteolytic activity (By similarity). Interacts (via C-terminus) with HSPG2 (via C-terminus). Interacts with EFEMP1/FBLN3 and LAMB3. Interacts with MMP9.