... func-tion of each of these enzymes, although they are presumed tobe active predominantly intracellularly [26,27]. Cathepsin H,cathepsin C, cathepsin F, cathepsin W, cathepsin B and cathepsin S are ... level of expression in cartilage, as well as a robust and significant increase in expression in OA. Cathepsin K is the only vertebrate enzyme outside the MMP family capable of degrading the collagen ... helped in collecting and processing tissue samples, and advised running and inter-preting low-density arrays. CJP and XSP designed the low-density arrays. CD and AC took patient consent and coordi-nated...