The study will utilize plasma samples from subjects participating in Cycle 6 of the Framingham Offspring Study. The Framingham Offspring Study is a longitudinal community based study initiated in 1971. A sample of 5,135 men and women, consisting of the offspring of the original Framingham Heart Study and their spouses were enrolled for the study, the objective of which was to identify common factors or characteristics that contribute to cardiovascular disease (CVD) by following its incidence over a long period of time in a large group of participants who had not yet developed overt symptoms of CVD or suffered a heart attack or stroke.