EGFR and non-small cell lung carcinoma: The up-regulated EGFR protein expression in the tumor (which possibly results in increased EGFR signaling) that was observed in some studies evaluating EGFR+ NSCLC, could be an explanation for our previously reported higher incidence of bone metastases in EGFR+ NSCLC compared with Kirsten rat sarcoma (KRAS+) and EGFR/KRAS wildtype NSCLC (14).