In a study of resistant and susceptible Merino sheep artificially infected with H. contortus and T. colubriformis, higher expressions of TLR2, TLR4, TLR8, TLR9 and TLR10 genes were found in the abomasal mucosa of resistant animals, which could be an indication of an early inflammatory response to infection [62]. Here, TLR4 is linked to infection.