CD19 and arthritic joint disease: We compared the gene expression profiles of IL-10eGFP+CD19+CD21hiCD24hiBregs, IL-10eGFP−CD19+CD21hiCD24hiB cells, and IL-10eGFP−CD19+CD21intCD24int follicular (FO) B cells isolated from arthritic mice (FO B cells do not produce IL-10 and do not suppress arthritis after adoptive transfer; Evans et al., 2007).