MRC1 and rheumatoid arthritis: For phenotypical analysis, M0 (ex vivo monocytes), M1 (GM-CSF-differentiated), and M2 (M-CSF-differentiated) macrophages derived from peripheral blood of HD or patients with RA were stained for FACS analysis with fluorescently labeled antibodies CD14-APC-Cy7, CD163-FITC, CD206-BV421, and CD86-PE.