Notch 4 signaling pathway plays an important role on the incidence and development of breast cancer. Notch 4 has little expression in normal mammary tissues, but it makes higher expression in breast cancer, especially in the triple negative breast cancer. The poor prognosis of breast cancer patients are usually related with Notch 4 high expression, which may be associated with the treatment resistance of internal secretion and its important effects on stem cells. This review describes the progress in the st...