The primary purpose is to determine the changes in gene expression induced by IFNb-1a (Rebif) and atorvastatin (Lipitor) combination therapy in patients with an isolated clinical syndrome suggestive of multiple sclerosis (MS), to identify markers of therapeutic response, and to predict patients' clinical response based on their in vitro response to this combination therapy measured by the gene expression levels in activated peripheral blood mononuclear cells (PBMCs).