THE RELATIONSHIP of serum cholesterol level to prevalence, incidence, and mortality from coronary heart disease (CHD) has been demonstrated in many epidemiological studies.<sup>1-6</sup>It is also known that serum cholesterol levels frequently can be influenced over long periods of time by available drugs. However, three key questions about such pharmaceutical agents need to be answered: Can they prevent the development of CHD? Can they prevent new CHD events or prolong life in persons already displaying clinical CHD? Are they reasonably free of adverse effects in long-term usage? The Coronary Drug Project—a nationwide collaborative study sponsored by the National Heart and Lung Institute—represents an extensive effort undertaken to answer the latter two of these questions with regard to men who have already experienced one or more verified episodes of myocardial infarction (MI).<sup>7-13</sup> As previously reported, three of the Coronary Drug Project treatment regimens were discontinued before the scheduled completion