• In patients with bone-predominant, minimally symptomatic metastatic castration-resistant prostate cancer as compared with those who received combination treatment, participants who participated in the control arm experienced a 3.2-fold increase in T cell responses (based on proliferation index)• Patients in the combination arm were more likely to have a PSA decline of more than 50% and to demonstrate longer progression-free survival and overall survival. The gene discussed is KLK3; the disease is prostate cancer.