F12 and rheumatoid arthritis: In RA SF, coagulation factor XII, SPARC-like protein 1, Rab GDP dissociation inhibitor beta and immunoglobulin gamma Fc region receptor III-A (FCGR3A) were notably upregulated; of which, activating FCGR3A has demonstrated important roles in sustaining the inflammatory response through the secretion of cytokines and proteases from the immune cell on which it is expressed [39].