MKI67 and breast cancer: In this ER+ breast cancer series, there was superior benefit for fulvestrant, with 81% CB and a median DoR of 25.8 (1.77–60.73) months, compared with previous reports of up to 60% CB and 4‐18 months response.3, 4, 6, 26, 27 Our series had substantial ER‐regulated proteins, modest EGFR/HER2 signaling and elevated Ki67 expression, a profile similarly equated to better outcome for other anti‐hormones.