KLK3 and posterior cortical atrophy: To evaluate the efficacy of the fucosylated form of PSA in distinguishing Gleason 6 (Gleason 3 + 3) and (Gleason 3 + 4) from Gleason 4 + 3 and Gleason 8 & 9, we stratified the Gleason 7 into two groups (Gleason 3 + 4, Gleason 4 + 3), then combined Gleason 7 (4 + 3) with Gleason 8, 9 into an AG PCa group, and Gleason 6 and 7 (3 + 4) into a NAG PCa group.