Consequently, the analysis of sequences from the RA patients also demonstrated a higher frequency of B cells expressing unmutated immunoglobulins, defined by <5 mismatches towards IMGT germline sequences in RA compared to healthy controls, in the IgM (81.2% vs 75.4%), IgA (7.3% vs 6.2%) and IgG (14.7% vs 8.7%) sequences (Fig. 3C–E). Here, CD40LG is linked to rheumatoid arthritis.