CCR6 and infection: Evaluation of infection-induced changes in CD4 T cell differentiation at Day 7 revealed a strong phenotypic shift to Th1 effectors (CXCR3+), Th1 polarized Tfh cells (CXCR3 + CXCR5+) and Th1 Th17 (CXCR3 + CCR6+) CD4 T cells (Fig. 1J, Figure S2A).