Given the clinical importance of PSA in PCa, we and others have earlier performed fine-mapping at the 19q13.3 locus near the kallikrein related peptidase-3 (KLK3) gene encoding PSA and have shown rs17632542, a non-synonymous SNP (amino acid change Ile to Thr at position 163), is the putative causal SNP at this locus associated with reduced PCa risk19–22; however, the exact role of PSA in PCa pathogenesis has not been fully elucidated. Here, KLK3 is linked to posterior cortical atrophy.