PCR-based cfDNA assays for oncogenic driver variants of genes such as EGFR in non-small cell lung cancer (NSCLC) and KRAS in colorectal cancer (CRC) showed high specificity (mean 96%) but only moderate sensitivity (mean 66%) when compared with tumor tissue assays, which are still the gold standard [39]. Here, EGFR is linked to non-small cell lung carcinoma.