ACAN and Arthritis: On the other hand, ADAMTS proteases are also involved in the pathogenesis of acquired and congenital connective tissue disorders, most prominently in arthritis, where ADAMTS4 and ADAMTS5 degrade aggrecan and contribute to the erosion of articular cartilage and joint degeneration (Glasson et al., 2005; Ilic et al., 2007; Song et al., 2007; Verma and Dalal, 2011; Santamaria, 2020).