Formation of the NITEGE (ADAMTS-cleaved) and DIPEN (MMP-cleaved) aggrecan neoepitopes and their detection with neoepitope antibodies can provide information about which enzyme is the major one that degrades aggrecan in mouse cartilage and has set a target for the development of new drugs designed to inhibit cartilage destruction in RA [22]. This evidence concerns the gene ACAN and rheumatoid arthritis.