SPARC encodes the human gene, Secreted protein, acidic, cysteine-rich (osteonectin). It may also be known as: SPARC; BM-40; Osteonectin; Secreted protein acidic and rich in cysteine; Basement-membrane protein 40; cysteine-rich protein; ON. The encoded protein has an amino acid length of 303 and a mass of 34.6 kDa. Other isoforms may exist. SPARC is a member of the SPARC family. Homologs of this gene exist in other organisms, including: Fly, Mouse, Rat, Zebrafish, Frog, Chicken.