ERBB2 and ductal breast carcinoma in situ: Combined inhibition of Notch and HER pathways, EGFR or HER2 via gefitinib or lapatinib, respectively has been investigated in a DCIS model by Farnie et al. to deduce the effects of dual inhibition of the Notch–EGFR/HER2 pathways on DCIS stem cells (109).