Therefore, prostate cancer cells can still survive at castrated testosterone level and develop into castration-resistant prostate cancer.[4] In our case, after 12 months of combined androgen blockade treatment, the PSA level of this patient was increased significantly and developed into metastatic castration-resistant prostate cancer (mCRPC), and the progression time was short and the development speed was fast, which may be related to the patient's higher Gleason score. The gene discussed is KLK3; the disease is prostate cancer.