To select a better breast cancer cell line in this experiment, ELISA was performed to verify the relative levels of JAG1 in conditioned medium of both breast cancer cells (MDA-MB-231, MCF-7), which showed that the JAG1 expression levels in MDA-MB-231 cells were slightly higher than that in MCF-7 cells (Fig. 2b). This evidence concerns the gene JAG1 and breast cancer.