EGF and lung carcinoma: Aberrant activation of EGFR drives tumorigenesis of various tumor types including lung carcinoma by activating downstream RAS-ERK and other pathways.29 TGIF2 is phosphorylated by the RAS-ERK pathway.10 We first confirmed that EGF was able to induce TGIF2 phosphorylation in H1299 cells (Fig. 5a), which could be inhibited by the EGFR inhibitor gefitinib and the MEK inhibitor PD98095 (Fig. 5b), suggesting that EGFR–RAS–ERK signaling could induce TGIF2 phosphorylation in LUAD cells as well.