APEX1 and breast cancer: Lucanthone is an autophagy inhibitor that is more potent than CQ at reducing breast cancer cell viability.46 Lucanthone is also able to disrupt topoisomerase II activity and inhibit APE1 – an important enzyme involved in DNA base excision repair.47, 48 Therefore, we assessed whether LS-1-10 is more efficient than lucanthone in reducing cancer cell viability.