In support of this hypothesis, a recent survey of Tfh cell responses in Plasmodium falciparum-exposed children revealed that a phenotypically and functionally distinct T helper 1 (Th1)-like Tfh cell subset (CXCR3+ CXCR5+PD-1+) is preferentially expanded during human malaria [14]. The gene discussed is CXCR5; the disease is malaria.