KLK3 and posterior cortical atrophy: In terms of PSA levels, 3 SNPs in GAS5 and BIRC5 had a positive association (OR = 1.08–4.079, highest: GAS5 rs17359906 G > A) in PCA patients with high(> 20 ng/ml) or low(PSA ≤ 20 ng/ml) PSA levels [16, 20].