TLR9 and infection: Neutropenic TLR9-/- mice were not protected from intracerebral infection with 1 × 104 CFU E. coli K1 by pre-treatment with 100 μg CpG ODN (P = 0.10, log-rank test; survival 14 days after infection 8% (2/25, CpG group) versus 36% (9/25, buffer group) (Figure 1D).