CD200R1 and rheumatoid arthritis: The expression of the MΦIFN-γ marker CD64, the positive MΦIL-4 marker CD200R, and the negative MΦIL-4 marker CD14 was similar in the synovial sublining of SpA and RA (Figure 1G through 1I) and was very low to absent in the intimal lining layer (data not shown).