<b><i>Case Presentation:</i></b> A 49-year-old obese man with prostate-specific antigen of 10 and preoperative Gleason score of 8 prostate cancer and initial staging of T<sub>3</sub>N<sub>0</sub>M<sub>0</sub> has undergone robot-assisted radical prostatectomy and extended pelvic lymph node dissection with unilateral nerve sparing. Here, KLK3 is linked to Familial prostate cancer.