EGFR and non-small cell lung carcinoma: Previous methods of EGFR mutation detection have been based on invasive approaches, such as surgical resection of tumours and needle biopsies.4 However, the heterogeneity of tumour tissue usually confounds the analysis of EGFR mutation load.5 Interestingly, recent data have shown that EGFR mutations can be found in plasma-derived cell-free DNA (cfDNA) from NSCLC patients.