Unbiased t-distributed stochastic neighbor embedding analysis gated on CD4+ T cells (Figure S1B) shows the small cluster of GC Tfh (Bcl6hiCXCR5hiPD-1hi) and the larger islands of hybrid Th1/Tfh cells (IFN-γ+IL-21+) generated in response to both infections. The gene discussed is CD4; the disease is infection.