PIP: Literature on steroid hormone receptors is reviewed. Cytosol and nuc lear estrogen receptors in the mammalian uterus, the mechanism of entry of estradiol into uterine cells, the regulation of the amount of uterine estrogen receptors, estrogen receptors in other organs and species, the chick oviduct system and progesterone receptors in the mammalian uterus, physiochemical aspects of progesterone receptors, the regulation of progesterone receptors, progesterone receptors, progesterone receptors in other organs and species, cytosol and nuclear androgen receptors in the rat ventral prostate and other organs and species, the regulation, genetic control, and plurality of androgen receptors, the distribution and ontogeny of glucocorticosteroid receptors, the relationships between cytosol and nuclear glucocorticosteroid receptors, mineralocorticosteroid receptors in the rat kidney and other organs and species, receptors of ecdysone, Vitamin-D and thyroid hormone, characteristics of receptor transformation, the nuclear receptor and fate of the receptor and hormone in target cell nuclei, the dependence of human cancers on hormones, the detection and characterization of steroid receptor interactions, and the physiological and pharmacological implications of steroid hormone receptors are discussed.