Chattoraj and colleagues observed that in a murine model at seven days post-infection with the lethal ehrlichiosis-inducing isolate, Ixodes ovatus Ehrlichia, there was significant upregulation of genes involved in Nod-like receptor signaling (nod2, nf-ΚB, nlrp1, nlrp12, pycard and il-1β), as well as Toll-like receptor 2 (tlr2). This evidence concerns the gene NOD2 and infection.