The nonparametric spearman correlation coefficient between the PSA-Gi level in BPH and total PSA in BPH was 0.3294 (95% CI, 0.1989–0.4559, p < 0.0001) and that between the PSA-Gi level in PCa and total PSA in PCa was 0.4613 (95% CI, 0.3531–0.5573, p < 0.0001) (Figure 3g). Here, KLK3 is linked to posterior cortical atrophy.