FCRL5 and systemic lupus erythematosus: We found that >95% of the BN cells activated with these defined stimuli resembled SLE patient T-bethi DN2 cells (Jenks et al., 2018) as the in vitro activated cells were IgDnegCD27neg T-bethiIRF4int, expressed the DN2 markers, CD11c and FcRL5, and were losing expression of CD21 and CXCR5 (Figure 4c–d).