At baseline, we confirmed that in RA patients, macrophages differentiated from monocytes with human SAB showed significantly fewer cells with the pan-macrophage markers CD11b and CD71 (p = 0.0005) as compared with HDs (Figure 1A) and fewer cells with expression of M2-like markers such as CD206 (p = 0.008) and CD163 (p = 0.0003) (Figures 1B, C). Here, TFRC is linked to rheumatoid arthritis.