NOTCH3 and breast cancer: Because our results indicate that NOTCH3-expressing cells originate in vMCF-7∆Raf1 xenografts (Fig. 3f), we employed the CRISPR-Cas9 gene editing technology to generate unique NOTCH3-knockout breast cancer cells (vMCF-7Raf-1 1GXCRISPR-NOTCH3) and assessed their stemness and invasive properties (Additional file 4: Figure S4 and Fig. 4a and b).