For example, in Leishmania major and Leishmania donovani infections, TLR2 may trigger host protective or non-protective immune responses; in Leishmania mexicana and Leishmania infantum infections, TLR2 mediates host protective responses; while in Leishmania amazonensis and Leishmania braziliensis infections, it may lead to disease exacerbation (36). This evidence concerns the gene TLR2 and infection.