Further studies indicate that the proteasome inhibitory and growth suppressive effects of CQ and 8-OHQ on tumor cells require their ability to bind copper and facilitate its transport into cells.462 Additionally, CQ (at a concentration of 50 μM) induces the oxidation of the copper chaperone ATOX1, indicating its inactivation and subsequent impairment of copper transport. This evidence concerns the gene ATOX1 and neoplasm.