Enforced expression of miR-34a in human cultured p53-mutant prostate cancer (PCa) cells induced cell-cycle arrest, apoptosis or senescence [122] and, most importantly, re-expression of this miRNA in CD44+ PCa cells blocked tumor progression and metastasis following orthotopic tumor cell implantation in immunocompromised mice [122]. This evidence concerns the gene CD44 and neoplasm.