Although serum prostate-specific antigen (PSA) has been extensively used as a diagnostic biomarker for clinical screening of patients with PCa, the specificity of this parameter is relative low (about 25 ~ 40%) when it is between 4.0–10.0 ng/mL, leading to a high rate of negative biopsy and overtreatment [3]. The gene discussed is KLK3; the disease is posterior cortical atrophy.