EGFR and metastatic neoplasm: Epidermal growth factor receptor (EGFR) mutational testing by circulating tumor (ct) DNA analysis demonstrated an adequate diagnostic accuracy [15–18] and has been recently incorporated in the clinical management of all EGFR-mutated NSCLC patients who progressed after first-generation EGFR tyrosine kinase inhibitors (TKIs) and in a subgroup of patients with newly diagnosed metastatic disease who cannot undergo tumor biopsy or received uninformative results from tissue molecular analysis [3].