KDM5 family members are H3K4 demethylases; JARID1B (KDM5B) is upregulated in prostate cancer tissues and acts as an AR coactivator [17], while JARID1C (KDM5C), overexpressed in prostate cancer, emerged as a predictive marker for therapy failure in patients after prostatectomy [19]. This evidence concerns the gene KDM5B and prostate cancer.