17-beta-hydroxysteroid dehydrogenases, such as HSD17B14, are primarily involved in metabolism of steroids at the C17 position and also of other substrates, such as fatty acids, prostaglandins, and xenobiotics. Has NAD-dependent 17-beta-hydroxysteroid dehydrogenase activity. Converts oestradiol to oestrone. The physiological substrate is not known. Acts on oestradiol and 5-androstene-3-beta,17-beta-diol (in vitro).