A recent study has shown that testosterone might have therapeutic benefits for patients with asymptomatic mCRPC (histologically confirmed prostate cancer, rising PSA levels following surgical or chemical ADT for at least 4 weeks, castrate serum testosterone ≤50 ng/dL, no cancer-related pain, ≤5 asymptomatic bone metastases, ≤10 total sites of metastases including soft tissue) [108]. This evidence concerns the gene KLK3 and Familial prostate cancer.