Despite the fact that none of single TLR3, TLR7 or TLR9 knockout yield an altered phenotype on cytokine response or enhanced susceptibility, we found that 3d mice are extremely susceptible to infection with T. gondii. Therefore, our results raise the possibility that combined action of nucleotide sensing TLRs is critical for host resistance to T. gondii. Here, TLR3 is linked to infection.