KDM5A promotes drug resistance of clinical drugs such as trastuzumab and erlotinib via deregulating p21 and BCL2-antagonist/killer 1 (Bak1) [5, 9, 22, 23], and facilitates the proliferation of many HER2-positive breast cancer cell lines through mediating cell cycle and apoptosis [5, 9, 12, 23, 29, 92]. Here, KDM5A is linked to breast cancer.