Baseline plasma EGFR mutation testing is now recommended in the College of American Pathologists (CAP)/International Association for the Study of Lung Cancer (IASLC)/Association for Molecular Pathology (AMP) guidelines for the molecular testing of patients with NSCLC as an alternative for a diagnostic tissue biopsy in cases with insufficient tumor tissue specimens or where tissue specimens are not obtainable; however, its prognostic value for predicting EGFR-TKI outcomes, which has been demonstrated in previous studies, has not yet been applied to clinical practice [31]. This evidence concerns the gene EGFR and lung cancer.