MERTK and rheumatoid arthritis: In RA patients as well as in controls, compared to M1 untreated macrophages, anti-TNF agents induced a significant modulation of polarization surface markers: (i) a decrease in M1 markers (CD40 and CD80), (ii) an increase in M(IL10) markers (CD16, CD163) and in the pan M2 marker MerTK (Figure 2, Supplemental Figure S1), and (iii) no effect on M(IL4) markers (CD206 and CD200R) (Supplemental Figure S2).