These treated PCa patients presented with significantly lower levels of PSA (0.33 ± 0.62 ng/mL; 3.50 ± 4.56 ng/mL, respectively) compared with their respective baseline pre-treatment samples (pre-prostatectomy 8.63 ± 5.54 ng/mL—pV < 0.0001; pre-radiotherapy 11.91 ± 24.68 ng/mL—pV = 0.0003), while these levels were higher than basal levels characterising HC (0.91 ± 0.5 ng/mL). The gene discussed is KLK3; the disease is posterior cortical atrophy.