We analyzed the gene expression profile obtained from the Cancer Cell Line Encyclopedia (CCLE) database and confirmed that epidermal growth factor receptor 1 (HER1 or EGFR), which contributes to the development and progression of breast cancer similar to HER2 (Nuciforo et al., 2015; Witton et al., 2003), is highly expressed in MDA-MB-468 cells (Supplementary Figure S1J). Here, EGFR is linked to breast cancer.