However, SB alone can be considered in patients with a negative PIRADS score (1–2) and low clinical suspicion of PCa (PSA density < 0.20 ng/mL/cc, negative DRE findings, no family history) and also when MRI is not available and a risk calculator indicates the need to perform a biopsy [34]. The gene discussed is KLK3; the disease is posterior cortical atrophy.