EGFR and neoplasm: Previous studies in EGFR nonselective patients revealed that patients with a higher baseline CEA level are more likely to respond to EGFR-TKIs and have longer PFS.13–15 This phenomena may be attributed to a higher EGFR mutation rate in patients with higher CEA levels.14,18 However, previous studies also revealed that higher CEA level was correlated with higher tumor burden and more advanced stage.19