TLR4 and infection: The contrasting role for TLR2 reported between our study and theirs could be explained by a differing role for TLRs in distinct sites of parasite replication (skin versus liver), route of infection (subcutaneous versus intravenous) and/or a different role for TLRs in the immune response to different species of Leishmania. Indeed, our results show that while the role for TLR2 is similar for L. mexicana and L. major infection, TLR4 plays a role only in infection with L. major.