RRS1 expression in normal mammary epithelial cell line MCF-10A and BC cell lines (MCF-7 and MDA-MB-231) was assessed by RT-qPCR and Western blot analysis, the results (Fig. 1h–i) suggested that RRS1 expression in BC cell lines MCF-7 and MDA-MB-231 was amplified, which was relative to that in normal mammary epithelial cell line MCF-10A, indicating that RRS1 was highly expressed in BC cells (P < 0.05). Here, RRS1 is linked to breast cancer.