Further studies of RNAseq analysis revealed that these CD11chi B cells from RA patients share mRNA expression profiles similar to that found in CD11chi B cells of SLE, including altered expression of CD19, CD11c, T-bet, FcRL5, CD32B, CD21, CD23, CD24, CD27, CD38 and CD40 compared to other B cell subsets (Supplementary Fig. 4f, g). Here, FCER2 is linked to rheumatoid arthritis.