A combination of androgen-deprivation therapy and surgical prostatectomy or radioablation has been used to treat therapy-naive patients with prostate cancer.39, 40 Although the initial response is typically efficient, almost all patients develop castration-resistant prostate cancer, frequently leading to patient death.41 Our current study provides a novel explanation of this phenomenon: androgen-deprivation therapy results in AR signaling inhibition, leading to KLF4 and miR-1 repression and potentially contributing to castration-resistant prostate cancer. The gene discussed is KLF4; the disease is prostate cancer.