Breast cancer is one of the most common cancers in the world with high heterogeneity.1 Using microarray and hierarchical clustering analysis, breast cancer can be divided into 5 “intrinsic” subtypes: luminal A, luminal B, Her‐2 overexpression, basal‐like and normal‐like, each subtype has its unique clinicopathologic features and treatment strategy.2 Here, ERBB2 is linked to breast cancer.