Studies used different human prostate cancer cell lines including PC-3 [26, 30–35], DU145 [28–31, 34, 36, 37], LNCaP [34, 35], CD44+/CD133+ HuPCaSCs [38], C4-2 [28], and 22RV1 [30, 37]. This evidence concerns the gene CD44 and prostate cancer.