Tumor genomic alterations such as discrete oncogenic variants (e.g. EGFR, PBRM1, LKB1, JAK1/2, and B2M mutations), complex rearrangements/copy number variations (e.g. programmed death ligand 1/2 [PD-L1/2] amplification), microsatellite instability, and TMB-related metrics can be detected in blood using next-generation sequencing (NGS) analysis of circulating tumor DNA. The gene discussed is EGFR; the disease is neoplasm.