EGF and breast cancer: To investigate whether any of the genes in the 194-gene signature were regulated in an EGFR-dependent manner, we queried a publicly available database of MCF-7 breast cancer cells that had been stably transfected with constitutively active kinases (Raf1, MEK1, ErbB2) or with wild-type EGFR, which was activated by short-term EGF treatment [18].