 Furthermore, mutations in the CYP17A1 gene are associated with rare forms of congenital adrenal hyperplasia, in particular 17α-hydroxylase deficiency/17,20-lyase deficiency and isolated 17,20-lyase deficiency.Overall, CYP17A1 is an important target for inhibition in the treatment of prostate cancer because it produces androgen that is required for tumor cell growth.Currently, the FDA has approved only one CYP17A1 inhibitor, abiraterone, which contains a steroidal scaffold that is similar to the endogenous CYP17A1 substrates.