Most genes were selected from the literature and have important roles in anabolic or catabolic pathways during osteoarthritis (for example, cartilage matrix proteins such as collagens, relevant degrading enzymes such as MMPs and aggrecanases, and genes from important catabolic [IL-1, tumor necrosis factor-α] and anabolic [BMP, transforming growth factor-β] signaling pathways). Here, TNF is linked to osteoarthritis.