While B cells enhance expression of FoxP3 and decrease expression of CD44 and T-bet by CD4+ T cells in the first two weeks after infection (Figs 3A–3C and S1G), we found expression of CD44, T-bet, and FoxP3 was similar in CD4+ T cells from WT and MD4 mice at one- and two-weeks post-infection (S5A–S5F Fig). This evidence concerns the gene CD44 and infection.