A core needle biopsy revealed the papillary structure of tumor cells (Fig. 2a), and IHC confirmed that ER staining was positive (ER Strongly Positive 90%) (Fig. 2b) and myoepithelial cells disappeared (CK5/6-, p63-, Calponin-) (Fig. 2a, d and e). The gene discussed is ESR1; the disease is neoplasm.