CD4 and rheumatoid arthritis: Since BACH2 is highly expressed in lymphocytes, including B and T cells, we examined BACH2 and Blimp1, and the results showed that BACH2 was inversely recruited to UBASH3A regions 1 and 2 in CD4+ T cells of RA patients (Fig. 3B), suggesting lowered SE activity of these eRNA-coding SE regions.