Compared with patients with HER2-positive disease, patients with HER2-negative disease were slightly younger (median age, 63.8 vs. 65.8 years) and fewer were male (64.7% vs. 75.6%); additionally, their primary tumor site was more likely to be gastric (75.6% vs. 58.1%) and to have diffuse histology (45.4% vs. 18.4%). Here, ERBB2 is linked to neoplasm.