MMP9 and rheumatoid arthritis: These concerns can only be addressed empirically in the clinic, but it is noteworthy that huAB1 treatment reduced the production of pro-inflammatory cytokines (IL-6, TNF, and IL-1β), chemokines (CXCL-8, GCP-2, MIG, IP-10, CCL-2, and CCL7), and MMPs (MMP-2 and MMP-9) in RA synovial tissue.