ALDH activity is also required for the synthesis of vital biomolecules through the metabolism of aldehyde intermediates, such as retinoic acid, folate and betaine, to name a few [2-4]. Whereas the ability of the ALDH family members to metabolise reactive aldehydes represents a major underlying cytoprotective mechanism, it is important to recognise that ALDHs demonstrate functions that extend beyond detoxification. Accumulating evidence supports roles for ALDHs in the modulation of cell proliferation, differentiation and survival, especially through participation in retinoic acid synthesis [2]. Members of this superfamily also exhibit functions that appear to be independent of their enzyme activity, including absorption of ultraviolet (UV) irradiation in the cornea by acting as a crystallin and binding to hormones and other small molecules, including androgens, cholesterol, thyroid hormone and acetaminophen [2,5,6].
