NOTCH1 and breast cancer: Our recent study has shown that enteric as well as mammary duct colonization with enterotoxigenic B. fragilis (ETBF), which secretes B. fragilis toxin (BFT), leads to mammary epithelial cell hyperplasia and higher breast cancer growth and stemness, and these oncogenic effects are mediated via β-catenin and Notch1 axes (42, 43).