To exclude the possibility that Bex may function via regulating its purported target, RAR/RXR, we treated PC-3 and Du-145 cells with Bex alone for 72 h with different concentrations within the clinical dosage range and found Bex concentrations below 8 μM have little influence on PC-3 and Du-145 proliferation (Fig. 3b), suggesting that Bex at a low concentration in PCa cells is unlikely to function through RAR/RXR to alter the DTX sensitivity. This evidence concerns the gene BEX3 and posterior cortical atrophy.