Members of this family are predominantly found in osteonectin and follistatin and adopt an EGF-like fold [1,2].

1: Crystal structure and mapping by site-directed mutagenesis of the collagen-binding epitope of an activated form of BM-40/SPARC/osteonectin. Sasaki T, Hohenester E, Gohring W, Timpl R; EMBO J. 1998;17:1625-1634. PMID:9501084

2: Crystal structures of the heparan sulfate-binding domain of follistatin. Insights into ligand binding. Innis CA, Hyvonen M; J Biol Chem. 2003;278:39969-39977. PMID:12867435