IFN-γ-producing TH1 cells are linked to resistance during liver-stage Plasmodium infection.284,285 In addition, IFN-γ-expressing CSP-specific TH1 cells reduce parasite burdens.286 However, CD4+ T-cell responses can also impair humoral immunity and expand self-reactive B cells.287 Within the first four days of infection, a dominant and phenotypically stable CXCR5+ TFH population emerges, resulting in a persistent CXCR5+ CCR7+ TFH/central memory T-cell response. This evidence concerns the gene CXCR5 and infection.