Such studies have defined key driver genes in prostate cancer and have enabled the deployment of therapeutic agents in molecularly defined disease subsets, including potent androgen receptor–targeted (AR-targeted) therapies (2, 3), poly(ADP-ribose) polymerase (PARP) inhibitors in BRCA1/2-altered prostate cancers, and immune checkpoint inhibitors in cancers with microsatellite instability (4–7). The gene discussed is AR; the disease is cancer.