Immunohistochemical analysis showed that the primary tumor exhibited two different histological features including triple‐negative components at lesion 1 (ER− PgR− HER2−) and hormone receptor positivity at lesion 2 (ER+ PgR+ HER2−); and all three metastasis sites were ER+ PgR+ HER2− (Fig. 3B). Here, ESR1 is linked to neoplasm.