In FY 1991, six grants were awarded under the title "Risk Factors in Early Human Atherogenesis" (RFEHA). The purpose was to extend the ongoing PDAY and to : obtain an adequate number of female cases so that risk factor associations could be accurately detected and studied; to increase the power of the study in general to detect associations of risk factors with raised lesions, which began to appear in this age group; and to increase the power of the study to detect genetic influences on atherosclerosis. REFHA added 1,400 new specimens to the 1,800 cases already collected in PDAY to achieve approximately 3,000 total specimens. Emphasis was placed on female cases and those that provided the best opportunity to study transition lesions between fatty streaks and fibrous plaques.