Many studies have prospectively verified the high specificity (92–100%) and positive predictive value (94.0–98.6%) of ctDNA-based EGFR mutation detection using tissues as a reference [26,27,28,29,30,31,32,33], and these two metrics have also been consistent in guiding the targeted therapy of NSCLC [30,31,34,35]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.