COL18A1 and rheumatoid arthritis: We show that the levels of CD147, endostatin, and proteasome 20S activity are not different between the two RA patient cohorts (Supplementary Figures S7A–C), whereas MMP-9 activity was reduced by cDMARDs (Supplementary Figure S7D), in accordance with their known ability to inhibit pro-inflammatory mediators (34).