Ctsk - cathepsin K

This gene encodes a member of the cathepsin family of cysteine proteases that is highly expressed in osteoclasts and is involved in the degradation of collagen and other matrix proteins in bone. The encoded preproprotein undergoes proteolytic processing to generate a mature, functional enzyme. Mice lacking the encoded protein exhibit phenotypic features of pycnodysostosis such as increased bone density and bone deformity, which become progressively more pronounced with age. [provided by RefSeq, Jan 2016]