To investigate the function of STC1 in breast cancer cells, we first evaluated the expression of STC1 in different breast cancer cell lines and found that the expression of STC1 in MCF-7 and ZR-7530 cells was low, while the expression in MDA-MB-231 (231) and MDA-MB-231 HM (231 HM) cells was relatively high (Supplementary Figures 1A,B). This evidence concerns the gene STC1 and breast cancer.