Aldo-keto reductase family 1 member C3 (AKR1C3), also known as 17β-hydroxysteroid dehydrogenase type 5 (17β-HSD5, HSD17B5) or 3α-hydroxysteroid dehydrogenase type 2 (3α-HSD2)[5][6][7] is a steroidogenic enzyme that in humans is encoded by the AKR1C3 gene.[8][9][10]