MMP1 and rheumatoid arthritis: SAA-induced cytokines [IL-6 [16], [41], IL-8 [14] and MCP-1 [14]] or MMPs [MMP-1, MMP-3 [21] and MMP-13 [17]] or cell adhesion factors [ICAM/VCAM [15]] were already described in previous studies but performed on RA- but not OA-synoviocytes.