Although the MMTV‐HER2/neu transgenic (HER2‐Tg) mouse model is classically considered a prototype for HER2‐positive breast cancer, its gene expression profile in tumors resembles that of the luminal subtypes,[46] and tumoral ERα in this strain was activated by DEHP (Figure S1G, Supporting Information). The gene discussed is ESR1; the disease is breast carcinoma.