It is acommon feature of a variety of metastatic epithelial tumorsincluding those of lung, breast and prostate cancer [14,15,16].Hypoxic regions of solid tumors were considered to be theprimary sites for the generation of the metastatic phenotype andhave been demonstrated to be chemo and radio-resistant [17,18,19,20,21].We have demonstrated that hypoxia inducible factor HIF-1induced the expression of DDX3 in two different breast cell linesby binding directly or indirectly to the hypoxia-responseelement (HRE) in the DDX3 proximal promoter [22]. This evidence concerns the gene DDX3X and prostate cancer.