Book excerpt: Recent Progress in Hormone Research, Volume 27 covers the proceedings of the 1970 Laurentian Hormone Conference held in Mont Tremblant, Quebec, Canada on August 29-September 4, 1970. The book discusses the x-ray analysis and the structure of insulin; spontaneous hyperglycemia and/or obesity in laboratory rodents; and the biological properties of the growth hormone-like factor from the plerocercoid of Spirometra mansonoides. The text also describes studies on human chorionic gonadotropin; studies on the structure of thyrotropin and its relationship to luteinizing hormone; and ultimobranchial follicles in the thyroid glands of rats and mice. The use of antibodies for characterization of gonadotropins and steroids; the biosynthesis of pregnenolone; and the metabolism and protein binding of sex steroids in target organs are also considered. The book further tackles the regulation of gene expression in Escherichia coli by cyclic AMP; the mechanism of action of ACTH; and the role of vitamin D and its relationship to parathyroid hormone and calcitonin. The text then encompasses the production and secretion of testicular steroids; the factors affecting the secretion of steroids from the transplanted ovary in the sheep; and the pilot gland approach to the study of insulin secretory dynamics. The analysis of the response to ACTH by rat adrenal in a flowing system is also looked into. Biochemists, physiologists, pathologists, endocrinologists, people working in laboratories of cancer research, chemical crystallography, and molecular biophysics will find the book invaluable.