MMP1 and rheumatoid arthritis: miR-203 was upregulated in synovial fibroblasts, in patients with RA, and elevated levels of miR-203 lead to enhanced secretion of MMP-1 and IL-6 via the NF-κB pathway and consequently lead to the activated phenotype of synovial fibroblasts in RA, thus; revealing that miR-203 is a proinflammatory factor in RA [21].