In a recent study evaluating the utility of ctDNA analysis by digital NGS of over 8000 advanced NSCLC, additional actionable biomarkers such as EGFR mutations, ALK and ROS fusion, BRAF V600E mutation, and Met 14 skipping mutation were identified in 29% of unvaluable or under genotyped tissue cases [29]. The gene discussed is ALK; the disease is non-small cell lung carcinoma.