This research program concerns studies of the chemical nature of intermediates in the biosynthesis of cholesterol, studies of the mechanism and stereochemistry of individual reactions involved in the biosynthesis of cholesterol and its further metabolism, studies of the alternative metabolism of mevalonic acid in normal and tumor cells, studies of the chemistry and metabolism of sphingolipid bases, studies of the metabolism of fatty acids, studies of the stereochemistry and mechanism of fumarase, and applications of mass spectrometry to the solution of biochemical problems. BIBLIOGRAPHIC REFERENCES: Knapp, F.F., Jr., Trowbridge, S.T., and Schroepfer, G.J., Jr., Concerning the Role of 4 beta-Methyl Sterols in Cholesterol Biosynthesis, J. Amer. Chem. Soc. 97, 3522 (1975). Knapp, F.F., Jr., and Schroepfer, G.J., Jr., Chemical Synthesis, Spectral Properties of Chromatography of 4 alpha-Methyl and 4 beta-Methyl Isomers of (24R)-24-Ethyl-cholestan-3 beta-ol and (24S)-24-Ethyl-cholesta-5, 22-dien-3 beta-ol, Steroids, 26, 339 (1975).