Cytosolic enzymes capable of oxidizing acetaldehyde to acetate have also been identified and characterized in vitro (Inoue et al. 1979) so a purely cytosolic pathway for ethanol oxidation to acetate and conversion to acetyl-CoA can be annotated. The role of this pathway in vivo is unclear, though limited attempts to correlate deficiencies in the cytosolic enzyme with alcohol intolerance have yielded suggestive data (Yoshida et al. 1989). Additional peroxisomal and microsomal pathways for the oxidation of ethanol to acetaldehyde have been described; their physiological significance is unclear and they are not annotated here.