Although the T790M second mutation in the mutant EGFR often occurs in NSCLC patients with acquired resistance to EGFR TKIs [85], HGF-dependent c-Met activation and constitutive activation by amplification of the MET gene are noted compensatory mechanisms that also are factors in acquired resistance in EGFR mutant NSCLC patients [86,87]. This evidence concerns the gene HGF and non-small cell lung carcinoma.