FKBP5 and cancer: To identify samples with impaired AR-signaling axis, from patients either exposed to ADT/ARIs or with metastases harboring ARNEG cancer cells, we examined nine AR-regulated genes (KLK3, KLK2, FKBP5, STEAP1, STEAP2, PPAP2A, RAB3B, ACSL3, and NKX3-1; refs. 26, 27).