When GEF is used for the treatment of EGFR2 overexpressing tumors, it results in dephosphorylation of EGFR2 and strong downregulation of PI3k/Akt signaling connected to dephosphorylation of EGFR3, which indicates the potential of GEF to be employed for EGFR2 overexpressing breast cancers in addition to EGFR overexpressing breast cancers. This evidence concerns the gene EGFR and breast cancer.