It was meaningful that we found that the free/total (F/T) PSA and AFU levels in the BPH patients were higher than in the PCa patients (F/T PSA: 0.22 ± 0.24 vs. 0.18 ± 0.19, p = 0.008; AFU: 20.16 ± 6.17 U/L vs. 18.21 ± 6.66 U/L, p = 0.049) (Table 1 and Figures 1A, B), but there was no line correlation between them (Figure 1E). Here, KLK3 is linked to posterior cortical atrophy.