To determine whether MET CN and expression can be used to monitor a patient ́s response to anti-EGFR therapy, we applied both analyses in 30 patients with metastatic head and neck, or NSCLC at longitudinal sampling points (before the anti-EGFR therapy, at 12 and 24 weeks after the therapy onset, and at disease progression). The gene discussed is EGFR; the disease is non-small cell lung carcinoma.