EGFR and cancer: Next-generation sequencing (NGS) of ctDNA enables comprehensive molecular profiling by identifying actionable drivers extended to somatic mutations (i.e., EGFR, ALK, ROS1), resistance-associated mutations (i.e., EGFR T790M), and co-occurring genomic alterations, thereby supporting early cancer detection, patient stratification, dynamic monitoring of disease progression, and evaluation of treatment response to guide personalized therapeutic decisions [71].