TLR9 and parasitic infectious disease: Consistently, P. yoelii-infected mice deficient for TLR9 had a reduction in CD11c+ T-bet+ B cells (Fig. 7a) and partial protection against malarial anaemia (Fig. 7b) that correlated with a mild but significant reduction (p < 0.05, Student’s t test) in circulating anti-PS IgG antibodies (Fig. 7c) compared to WT controls at days of similar parasitemia (Fig. 7d).