The science of "steroidology", initiating with the discovery of cholesterol as the major sterol found in mammals, has captured significant scientific attention and recognition. The development of antifungal agents with a specific target site in the biosynthesis of fungal sterols was initiated in the late 1960s with the discovery of antifungal activities inherent to azole derivatives. The principles of sterol nomenclature are relatively simple. They are based on a numbering system and three series of sterol prototypes, the cholestanol, ergostanol, and stigmastanol series. Sterols have been long known as membrane components predominantly localized in the plasma membranes of sterol-requiring organisms.156-158Sterols have long been known to interact with phospholipids and to maintain optimal membrane fluidity and integrity under changing environmental conditions. Steroid hormones are synthesized from sterols as their immediate precursors and comprise one of the major classes of regulatory compounds.