In this study, we compared the variant detection in 137 plasma samples of patients with NSCLC using the UltraSEEKTM Lung Panel on the MassARRAY® System (Agena Bioscience, San Diego, CA, USA), a new highly-sensitive method to detect 67 mutations across 5 genes (EGFR, BRAF, KRAS, ERBB2 and PIK3CA) in a one PCR multiplex assay, with the standard method Cobas® EGFR Mutation Test v2. Here, EGFR is linked to non-small cell lung carcinoma.