To investigate the biological function of TIPE1 in breast cancer cells, we measured the expression levels of TIPE1 in breast cancer cell lines, including a non-cancer cell line (MCF10), a Her2-positive cell line (SKBR3), triple-negative cell lines (MDA-MB-231 and MDA-MB-468), and an ER-positive cell line (MCF-7). Here, ERBB2 is linked to breast cancer.