Prostate cells also express CYP3A4 that can inactivate T by conversion to mainly 6βOH-T (with 2β-, 15α/β- and 11β-hydroxyl side product formation (Niwa et al., 2015)) and a decrease of CYP3A4 expression is observed in prostate cancer (Fujimura et al., 2009). Here, CYP3A4 is linked to prostate cancer.