EGFR and neoplasm: There were additional noteworthy observations from our patients treated with anti-EGFR–based therapies: three of five patients whose EGFR amplification was only detected in cfDNA (negative on tissue NGS) still demonstrated a PR (including one patient treated with cetuximab monotherapy [patient 57]), PRs were seen across different degrees of EGFR amplification status (from copy number amplification of 2.37 to 143.94), and three of four patients who received dual anti-EGFR inhibitors (coadministration of antibody and tyrosine kinase inhibitor for EGFR) achieved tumor reduction.