ERBB2 is a proto-oncogene that is overexpressed in approximately 25% of breast cancers, but also in gastric and other cancers, leading to malignant transformation of epithelial cells (Slamon et al., 2011; Fang et al., 2017; Galli de Amorim et al., 2019). Here, ERBB2 is linked to breast carcinoma.