Instead it first caused a temporary expansion of CXCR5−IL-4gfp+ Th2 cells and CXCR5+ IL-4gfp+ Tfh cells within the draining LN, followed by the appearance of functionally superior IL-4gfp+ Th2 cells at the infection site 20 days later. The gene discussed is CXCR5; the disease is infection.