Women are endowed with certain advantages. They face fewer hazards than the male, whom they tend to outlive. In infancy and childhood mortality among boys is greater than in girls, and in middle life ischaemic heart disease takes a much greater toll among men. The Registrar-General's figures tell us, for instance, that in the five-year period 1953-7 the mortality from coronary artery disease in the age-group 55-59 years was four and a half times higher for men than for women. Age and sex may thus influence the development and progression of vascular disease. Life expectancy for the female now exceeds that of the male by a greater number of years than ever before. Hence a closer study of the "feminine" response to long-term cardiovascular damage ought to increase our understanding of the basic processes involved.