Prostate specific antigen (PSA) is a protease whose function is to break down the high molecular weight protein of the seminal coagulum into smaller polypeptides. This action results in the semen becoming more liquid. PSA is produced by epithelial prostatic cells, both benign and malignant.
This is a companion discussion topic for the original article at https://patient.info/doctor/oncology/prostate-specific-antigen-psa