STAT3 and neoplasm: As a proproliferative, proinvasive and antiapoptotic protein on the cell membrane, the dimerization and autophosphorylation of EGFR stimulate its intrinsic intracellular protein tyrosine kinase activity and initiates downstream pleiotropic oncogenic signaling cascades, including the Ras/MEK/ERK,46,47 PI3K/Akt/mTOR,25,26,48,49 and STAT3 pathways.50,51 Gef inhibits EGFR tyrosine kinase and leads to the disruption of downstream signaling transduction, thus inhibiting the growth and invasion of tumor cells.