Malaria studies in mice models have shown that CD4 + T cell intrinsic Bcl6 signalling is required for induction of Tfh responses [106], and that the cytokines IL-6 and IL-21 are also required [107,108] whereas the presence of Type 1 IFN tended to compromise Tfh cells and Tfh-mediated GC responses [109]. The gene discussed is CD4; the disease is malaria.