Cumulative data from clinical studies and retrospective studies indicate that the ER status might affect the therapeutic efficacy of paclitaxel because paclitaxel is less effective in patients with ER+ breast tumours than in patients with ER‐ breast tumours.5, 41 However, most of these data were obtained from comparative studies in tumour cell lines extracted from different patients. Here, ESR1 is linked to breast neoplasm.