It is reported that AKR1C3 is a pivotal enzyme in converting Δ4-dione to testosterone [13], 5α-DHT to 3α-diol [7], and androstenedione and dehydroepiandrosterone (DHEA) to intraprostatic testosterone in the progression of PCa and CRPC. This evidence concerns the gene AKR1C3 and posterior cortical atrophy.