The sEGFR level was not related to tumor EGFR expression (4.2 for ≤ 10% versus 4.2 ng/mL > 10% EGFR staining, P = 0.8), [89Zr]Zr-cetuximab blood concentration on PET, or %ID in the liver (a potential “sink” organ for cetuximab-sEGFR complexes; P = 0.33 and P = 0.62 respectively). This evidence concerns the gene EGFR and neoplasm.