Book excerpt: The Biology of Cholesterol and Related Steroids focuses on the study of sterols in relation to living organisms. The publication first takes a look at the analysis of sterols and related steroids and the distribution of sterols and related steroids in nature, as well as the processes of extraction and separation and presence of sterols in plants, fungi, vertebrates, and invertebrates. The text then ponders on biosynthesis of sterols and metabolism of cholesterol. Topics include formation of fatty acid esters of cholesterol, steroid hormones, biosynthetic pathway to sterols, reaction mechanisms, and comparative aspects of sterol synthesis. The manuscript examines the developmental aspects of cholesterol metabolism and sterols in biological membranes. The book also reviews cholesterol synthesis in animal tissues, sterol metabolism in isolated cells, and epidemiology of the plasma cholesterol. Discussions focus on selection of statistical populations, genetic influences, regulation of sterol synthesis, general aspects of sterol metabolism, and removal of cell cholesterol in vivo. The publication is a dependable source of data for biochemists and readers interested in the biology of cholesterol and steroids.