In relation to PSA levels, most PCa cases and benign prostatic hyperplasia (BPH) controls (32 out of 37 individuals 86.5%) fail within the “grey zone” of PSA diagnostic value (4–10 ng/mL); only 5 individuals showed slightly higher PSA values (11.9–17.7 ng/mL). The gene discussed is KLK3; the disease is benign prostatic hyperplasia.