Similar to ERRα loss-of-function in BC cells (Fig. 1e–j), SKBR3 cells treated with lapatinib, a dual epidermal growth factor receptor (EGFR)/human EGFR-2 (HER2) tyrosine kinase inhibitor approved for patients with HER2-amplified breast tumors, decreased both ERRα and DNMT1 protein levels (Supplementary Fig. 4e). Here, DNMT1 is linked to breast cancer.