ERBB2 and breast cancer: In addition to signaling pathway inhibitors such as Notch and γ-secretase inhibitor (MK-0752), hedgehog inhibitor (Vismodegib, GDC-0449), Wnt signaling pathway inhibitor (PKF118-310 and pyrvinium pamoate), PI3K/Akt/mTOR pathway inhibitor (Everolimus, RAD001), CXCR2 inhibitor (Reparixin), and EGFR/HER2 inhibitors (Lapatinib and Herceptin), which target signaling pathways directly (110), offer several breast cancer treatment strategies via targeting BCSCs.