APOE and atherosclerosis: To investigate that the immunologic mechanisms involved in the pathogenesis of atherosclerosis, Apo E−/− mice, a well-known spontaneous hypercholesterolemia and atherosclerosis model, were fed with a regular diet over a 48-week period, the serum level of total cholesterol and IL-6 as well as the proportion of two atherosclerosis related pro-inflammatory (Th1 and Th17 cells) and regulatory T cell subsets were examined at age 6, 12, 24 and 48 weeks.