FOXJ2 and rheumatoid arthritis: SLAMF8 is an essential surface receptor that is highly expressed on monocytes and has been implicated in the progression of autoimmune diseases such as RA.[20] Moreover, FOXJ2 regulated SLAMF8 by directly binding to the SLAMF8 promoter (Figure 3G; Data S3, Supporting Information), with a 21.6‐fold increase in the binding of FOXJ2 to the SLAMF8 promoter compared with the nonspecific binding of IgG to the SLAMF8 promoter (Figure 3H).