With regard to the anti-catabolic activity, the ability of OP-1 to counteract various pro-inflammatory/catabolic responses or directly inhibit expression of catabolic mediators was previously shown in primary chondrocyte cultures or in animal models of post-traumatic osteoarthritis or disc degeneration [17-19,24,31]. This evidence concerns the gene BMP7 and intervertebral disk degenerative disorder.