EGFR and lung cancer: Of 175 MPM patients, there were only 84 patients who had EGFR mutation status, 25 cases were detected by the methods of direct sequencing while 59 cases were detected by the methods of ARMS, There are only 84 patients subjected to EGFR mutation analysis because EGFR mutation analysis was not becoming the routine clinical practice until 2009, what’s more, the quality and quantity of a portion of lung cancer specimens was unqualified or not enough for the EGFR mutation analysis and these patients denied re-biopsy or the performance status(PS) was not suitable for re-biopsy.