Conversely, on day+25, the ratio between CD4+CXCR5+Foxp3+ follicular T regulatory cells (Tfr) and CD4+CXCR5+Foxp3- follicular helper T (Tfh) cells was markedly increased in both mLNs (Figure 5A) and pLNs (Figure 5B) of CpG-proB recipients relative to their counterpart in control mice undergoing GVHD. The gene discussed is CXCR5; the disease is graft versus host disease.