MKI67 and breast cancer: In 2011 Cuzick and colleagues reported that, in the Arimidex, Tamoxifen, Alone or in Combination trial, the quantitative ER Histo (H)-score alone or in combination with three other markers (progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67) was associated with risk of distant recurrence in postmenopausal women who were diagnosed with ER-positive breast cancer [11].