Notably, the functional Breg cells polarized from CD24hiCD38hi or CD24hiCD27+ B cells displayed a phenotype unrelated to CD24hi, CD27+, and/or CD38hi (Fig. 1k), which is consistent with the finding that, in the blood of SLE patients, increasing frequencies of functional Breg cells were accompanied by decreasing ratios of CD24hiCD38hi and CD24hiCD27+ B cells (Fig. 1a, c). This evidence concerns the gene CD27 and systemic lupus erythematosus.