The study of Kiechl et al. assessing the progression of carotid atherosclerosis by duplex ultrasonography found that subjects with the Asp299Gly TLR4 SNP had a lower risk of carotid atherosclerosis, smaller carotid intima-media thickness, as well as reduced levels of pro-inflammatory cytokines and acute phase reactants when compared to the wild-type control group [60]. Here, TLR4 is linked to carotid atherosclerosis.