In LNCaP and LNCaP-AR cells, KLF4 messenger RNA (mRNA) and protein levels increased after dihydrotestosterone (DHT) treatment (Figures 1b and c), but decreased after treatment with MDV3100, an AR antagonist22, 23 (Figures 1d and e), suggesting an association between KLF4 and AR signaling in the same cell signaling pathway in AR-positive prostate cancer cells. This evidence concerns the gene KLF4 and prostate cancer.