The expression levels of FOXP2 varied among different breast cancer cell lines (Figure S2), in which the epithelial-type cell lines such as MCF-7 and HCC1397 exhibited higher levels of FOXP2 than that of the mesenchymal-type cell lines such as MDA-MB-231, MDA-MB-453, and MDA-MB-436. The gene discussed is FOXP2; the disease is breast cancer.