Similar positive association of EGFR gene copy number with outcome to EGFR-TKIs was found by our UCCC laboratory in three distinct cohorts treated with the EGFR TKI gefitinib [23,32,34] and in an advanced NSCLC cohort treated with erlotinib in which the molecular markers were evaluated at the Princess Margaret Hospital in Toronto, Canada (22). The gene discussed is EGFR; the disease is non-small cell lung carcinoma.