Jagged1-mediated Notch signaling activation was able to activate the EMT process and increase migration and invasion in breast cancer mainly though upregulation of N1ICD, rather than Notch2 NICD (N2ICD), Notch3 NICD (N3ICD), or Notch4 NICD (N4ICD). This evidence concerns the gene NOTCH4 and breast cancer.