EGFR and lung cancer: To study the mechanism underlying the tyrosine kinase inhibitor (TKI) resistance in non–small cell lung cancer (NSCLC), application of the strategy to four NSCLC cells harboring different epidermal growth factor receptor (EGFR) mutations reveals significantly differential 1559 glycopeptides and 1949 phosphopeptides either in EGFR mutation or TKI-resistant cells.