RTHEROSCLEROSIS is generally considered to be the major disease of this era. Its consequences in the coronary, cerebral, and peripheral arteries, in the form of occlusive phenomena, are responsible for more death and disability than any other disease. In spite of much study and research there is still no agreement con-cerning the sequence of pathogenetic events, etiol-ogy, or treatment of atheroselerosis. The not-too-rare occurrence of coronary artery occlusions (almost always a consequence of atherosclerosis) in young men from 20 to 40 years of age testifies to the fallacy of the idea, still prevalent, that atherosclerosis is a problem of the aged or senile. For the male it is a

1 This work was sul) porte (l (in part) by the Atomic Energy Commission and the United States Public Health Service. Tlhe authors wish to acknowledge with gratitude the generouls and (1 invaluable advice and assistanne given by Profs. Ilarilin B. Jones and John H. Lawrence.