ESR1 and breast carcinoma: To expand our observation to another cell type and test if Luminal A-type cells are hypersensitive to FBXW7 knockdown, we achieved stable integration of doxycycline-inducible FBXW7 shRNA in the T47D breast cancer-derived cell line, which harbors a Luminal A-like signature (ER/PR-positive, Her2-negative, overexpresses luminal-specific cytokeratins 8 and 18).