Another possible reason is that somatic mutations accumulated by aging cells restrict the utility of ctDNA.7, 8 At the same time, a number of studies have shown that the efficacy of EGFR‐TKI in patients with EGFR‐mutant NSCLC is only about 70%, which may be related to the activation of the bypass signaling pathway to cause primary resistance.9, 10, 11 However, there is currently no clinically relevant marker to predict the efficacy of EGFR‐TKI. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.