(4) Can Patients Who Are at High Risk of Developing PCa Be Placed on TRT? There has been an increasing trend in using transrectal prostate biopsy procedures after the widespread use of PSA which naturally resulted in increasing diagnosis of prostatic intraepithelial neoplasia (PIN) and atypical small acinar proliferation (ASAP) independent of PCa. Here, KLK3 is linked to prostate intraepithelial neoplasia.