The study will evaluate the role of genetic variation in inflammatory pathway genes at 29 loci on the risk and progression of carotid artery atherosclerotic disease (CAAD). Genes to be evaluated include those potentially involved in plaque initiation and progression. The investigators will evaluate single nucleotide polymorphisms (SNPs) informative for the common locus haplotypes. Choice of informative polymorphisms for evaluation is based on the genes' evolutionary history. They will evaluate progression effects in subjects with CAAD followed longitudinally by noninvasive magnetic resonance (MR) techniques over 3 years. Risk will be evaluated by case-control comparisons. In additions to evaluating genetic polymorphisms, they will evaluate the intervening phenotypes of protein level for fibrinogen, C-reactive protein, serum amyloid A, and interleukin-6. Independence of genetic predictors from traditional cardiovascular risk factors will be evaluated.