ADAMTS1 and arthritic joint disease: Known functions of ADAMTS proteases include maturation of procollagen (ADAMTS2, 3 and 14) and von Willebrand factor (ADAMTS13) as well as extracellular matrix (ECM) cleavage involved in morphogenesis (nematode ADAMTS proteins), angiogenesis (ADAMTS1 and 9), ovulation (ADAMTS1), cancer (ADAMTS4, 5, 9 and 15) and arthritis (ADAMTS5) (Apte, 2009; Hubmacher and Apte, 2015).