ACAN and arthritic joint disease: Specific cleavage with ADAMTS-5 in aggrecan exposes the ARGS neo-epitope; the N-terminal neo-epitope after cleavage of the NITEGE373↓374ARGSV bond in aggrecan [15] The ARGS fragment is rapidly excreted from the ECM in cartilage explant culture models and is also present in serum, urine and synovial fluid of arthritis patients [16,17].