ESR1 and neoplasm: Immunostaining of estrogen receptor (ER) and progesterone receptor (PgR) was evaluated by using the Allred score and the Allred scores were positive (proportion score [PS] 1 (< 1%), intensity score [IS] 2) and negative (PS 0, IS 0), respectively.12,13 The tumor was human epidermal growth factor 2 (HER2)–negative (immunohistochemistry [IHC] 0).