MET and lung carcinoma: Engelman et al. [12] constructed 18 lung cancer cell lines resistant to Gefitinib or Erlotinib (EGFR tyrosine kinase inhibitors) and found that MET amplification might promote cellular resistance to EGFR target therapies, and Guix et al. [13] found that the absence of expression of Insulin-Like Growth Factor (IGF) is associated with the resistance to EGFR inhibitors in A431 lung squamous cancer cells.