Since osteoarthritis and intervertebral disc degeneration are both degenerative diseases of skeletal joint regions, and because many of the genes expressed in cartilage are also expressed in the intervertebral disc, we tested whether asporin could mediate aggrecan and collagen Π expression in human nucleus pulposus cells during disc degeneration. The gene discussed is ACAN; the disease is Intervertebral disk degeneration.