CYP17A1 and prostate cancer: Abiraterone, a pyridine-substituted pregnenolone-derived inhibitor of steroidogenic CYP17A1 used as a first-line treatment of prostate cancer, cross-reacts with human enzymes CYP11B1, CYP21A2, as well as CYP1A1, CYP2C9 and CYP3A45,6.