A cohort of patient-derived mouse xenograft benefited from cetuximab and trastuzumab over gemcitabine for the treatment of human pancreatic cancer; however, in a cohort of pancreatic cancer patients, a clinical trial assessing trastuzumab (not tested for HER2 amplification) showed no significant response. This evidence concerns the gene ERBB2 and familial pancreatic carcinoma.