ERBB2 and breast cancer: Pathological analysis of these biopsies revealed changes suggestive of mild reflux esophagitis with no evidence of malignancy in the esophagus, signet ring cell adenocarcinoma diffusely involving lamina propria in the gastric body, gastric antrum, duodenum, and ascending colon. Immuno-histochemistry was strongly positive for GATA-binding protein 3 (GATA3), estrogen, and progesterone receptors, with HER2 negative, consistent with metastatic BC (Figure 4).