Immunohistochemistry showed the tumor was diffusely strongly positive for estrogen receptor (ER) (Fig. 3D), and about 20% of tumor cells were positive for progesterone receptor, while her-2 protooncogene expression was negative and ki-67 index was 20%; negative for CK5/6, P63 and calponin (Fig. 3E). Here, ESR1 is linked to neoplasm.