KLK3 and posterior cortical atrophy: Although the conventional blood PSA test results showed that the PSA levels of PCa patients decreased significantly at 3 months after surgery (p < 0.001; Figure 8), when compared with BPH patients, there were still a few PCa patients with relatively low PSA values or BPH patients with relatively high PSA levels; as such, it may be difficult to accurately determine the diagnosis of PCa when using PSA levels alone (Figure 8).