ATOX1 and breast cancer: Indeed, a role for ATOX1 in tumor growth and metastasis has been identified in breast and colon cancers.22,34,38,39 However, in HEK293T and MDA-MB-231 breast cancer cells investigators detected a substantial interaction between ATOX1 and components of the anaphase promoting complex, a key regulator of cell proliferation, that were not detected in this study.40 This discrepancy may be related to differential functions and/or protein-protein interactions of ATOX1 in myoblasts compared to cancer cells or species specific functions of ATOX1.