HES1 and breast cancer: Our results revealed a significant upregulation of cleaved, active Notch1 intracellular domain (N1ICD) and canonical Notch1target HES1 in adjacent breast cancer cells (Co-MCF-7-mRFP) of SEN-MCF-7, compared with that in MCF-7-mRFP cultured with senescence culture medium (SEN-CM-MCF-7-mRFP) (Figure 3B).