Structure of SPARC protein. A ribbon diagram derived from crystallographic data shows the three modular domains of SPARC. Representative activities attributed to each domain are shown beneath the designated amino acids. The follistatin-like domain contains the peptide 2.1 (see ref. 1) shown in green and the (K)GHK angiogenic peptide (amino acids 114–130) shown in black. The E-C domain contains the amino acids 255–274 (peptide 4.2) shown in yellow. Adapted from Hohenester et al. (29) and the Brookhaven Protein Database (30), accession no. 1BM0 from Ref.1, with permission.