Formaldehyde dehydrogenase is a very important enzyme, which breaks down the highly poisonous formaldehyde into the not so poisonous formate. Found only in small quantities (possibly reflecting the small amount of formaldehyde that would be found in a 'natural' environment) but highly conserved through a large swathe of the living world, including most vertebrates, giving an indication that this enzyme may be essential to life. It will also catalyse the dehydrogenation of ethanol, though poorly, giving rise to the theory that it is the progenitor of the various alcohol dehydrogenases, throughout the animal world.