EGFR and lung cancer: A negative regulator of EGFR, mitogen-inducible gene 6 (MIG6) is a target of miR-200, the ratio of the expression of MIG6/miR200c was found to be tightly correlated with EMT and resistance to erlotinib in lung cancer in vivo, in which the MIG6 (mRNA)/miR200 ratio was inversely correlated with response to erlotinib, indicating that the ratio of MIG6/miR200 may be a predictive biomarker of the response of lung cancer to EGFR-TKIs [57].