NOTCH1 and breast cancer: In line with our previous work where high Notch increased the proliferation and survival of MDA-MB-231 cells [18], our study demonstrates that high Notch1 activity caused resistance to applied HDIs, while low or normal Notch activity sensitized cells for the HDIs applied separately and in combination with CDDP, showing that Notch1 activity influences treatment efficiency in luminal-type BC cells.