NOTCH1 and breast cancer: Notch1 inhibition has also been reported to cause an increase in liver metastases from neuroblastoma and breast cancer cells and may support early angiogenesis and growth of micrometastases within the liver.19 The preclinical studies noted that tarextumab treatment alone and not combination therapy, decreased Notch1 intracellular domain levels in the xenograft OMP‐PN17 PDAC tumor.