EGFR and cancer: Although age and sex were matched for the three cohort, the presence of druggable mutation is not matched due to the ethnicity and cancer stages: the cohort of 3DMed cfDNA samples are from Chinese late stage NSCLC patients, which includes higher EGFR mutation rate and lower KRAS rate; the cohort of MSKCC-IMPACT samples are mostly US late stage NSCLC patients and TCGA NSCLC cohort is mostly US early stage NSCLC patients.