Some clinical details have been obfuscated for privacy purposes. Our patient was a gentleman in his 60s who presented with a chief complaint of a rising prostate-specific antigen (PSA) approximately 10 years after low dose rate (LDR) brachytherapy for prostate cancer. Originally, he had presented in his 50s with a Gleason 3+4 (Grade group 2) prostate cancer, with pre-treatment PSA <10, and non-palpable (T1c) disease. At the time of initial prostate cancer presentation, staging scans (CT of the abdomen and pelvis and nuclear medicine bone scan) were negative for metastatic disease. Here, KLK3 is linked to Familial prostate cancer.