Immunohistochemical (IHC) staining indicated that the lesion was estrogen receptor(ER) negative (Fig. 2a), progesterone receptor(PR) negative (Fig. 2b), C-erbB-2 positive carcinoma in situ (3 +; Fig. 2c) and thyroid transcription factor-1(TTF-1) negative(Fig. 2d). Here, ESR1 is linked to in situ carcinoma.