Decorin compositions and use thereof

A method of producing a non-gagylated decorin core protein comprising:

• providing host cells expressing non-gagylated decorin core protein from a retroviral vector, wherein said non-gagylated decorin core protein is encoded by a nucleic acid sequence that is at least 95% identical to SEQ ID NO:7;
• culturing said host cell so that said non-gagylated decorin core protein is produced;
• and
• purifying said non-gagylated decorin core protein to provide a decorin core protein composition comprising less than 100 ng residual host cell protein/mg decorin core protein in said composition and less than 20 pg residual host cell DNA/mg decorin core protein.