In contrast, Fang et al. showed that active AOSD is paralleled with an increased percentage of “naïve” IgD+CD27– B cells, double-negative IgD–CD27– B cells as well as CD20–CD27hi plasmablasts, whereas the “regulatory” B-cell subsets—IgD+CD27+ and CD24hiCD27+—significantly decreased [40]. This evidence concerns the gene CD27 and adult-onset Still disease.