CD14 and rheumatoid arthritis: Finally, OA- and RA-EVs display similar cellular origin as indicated by Fluorescence Activated Cell Sorting (FACS) analysis where we labeled EVs against the following panel of markers: CD177 (for neutrophils origin), CD14 (for monocytes origin), CD62E (as a marker of activated epithelium), CD25 (as a marker of T-reg cells).