Consistent with previous reports [17], WT mice were highly susceptible to lethal IOE challenge where six of six WT mice succumbed to infection on days 9 and 10 p.i. Notably, while TLR2-/- had increased susceptibility to IOE infection with six of six mice succumbed on days 7 and 8 p.i., all Nod2-/- mice survived till days 15 p.i. (Fig. 4A). This evidence concerns the gene NOD2 and infection.