The most persuasive prima facie case for involvement of a particular factor in atherogenesis arises when epidemiological and experimental data agree. This is true for only a few of the many risk factors that have been proposed. Undoubtedly, the best known is high plasma levels of low-density lipoprotein (LDL) cholesterol. However, plasma cholesterol levels nearer the average are not reliable predictors of an individual’s risk; other factors must be involved. There is increasing evidence, both experimental and human, that oxidative processes may be the missing link...