In lupus-prone Roquinsan/san mice, the deficiency of IL-17A significantly abrogated nephritis development, together with increased numbers of CD1d+CD5+ Bregs, Foxp3+CD25+CXCR5+ follicular regulatory T cells (Tfr), but decreased numbers of CD4+ICOS+CXCR5+PD1+ follicular helper T cells (Tfh) and GC B cells [126]. The gene discussed is CXCR5; the disease is systemic lupus erythematosus.