CYP17A1 and hypertensive disorder: In this article, we summarise our research into common functional polymorphisms, at three steroidogenic loci that we believe contribute to the heritable component of blood pressure: CYP11B2, CYP11B1 and CYP17A1. We then discuss the importance of corticotropin (ACTH) to the regulation of all three genes, present evidence to suggest that this is an underappreciated factor in the long-term regulation of aldosterone secretion, and propose that the differential response of these polymorphic loci to ACTH may predispose their carriers to raised blood pressure and, ultimately, hypertension.