EGFR and non-small cell lung carcinoma: In addition to primary resistance, secondary resistance to EGFR TKIs in EGFR-mutant NSCLC patients is commonly acquired through different mechanisms: about 50% of the tumours develop a secondary EGFR mutation in threonine 790 (T790M)9, whereas approximately 20% have tumours with amplification of the proto-oncogene MET10.