Furthermore, multiple of these reports demonstrated the longitudinal tracking of EGFR mutant TR-ctDNA in non-small cell lung cancer patients over time, including one study that pursued high time-resolution urine collection (i.e., daily collection) and found associations between TR-ctDNA kinetics early during therapy and treatment outcomes (Husain et al. 2017). Here, EGFR is linked to non-small cell lung carcinoma.