Our previous study indicated that blood, in particular serum, is a good substitute when tumor tissue is absent or insufficient for testing EGFR mutations to guide EGFR TKIs treatment in patients with NSCLC.[24] However, this study neither evaluated the accuracy of different EGFR mutation testing methods in blood samples for predicting response to EGFR TKIs nor performed subgroup analysis for the associations of EGFR mutations with clinical outcomes according to blood EGFR mutation testing methods. Here, EGFR is linked to non-small cell lung carcinoma.