ESR1 and breast cancer: For death, while ER−/PR+/HER2+ seems to increase the risk of death more than ER−/PR+/HER2− in comparison with ER+/PR any, a study by Bae et al. reported that single positive hormone receptor profiles are associated with poorer disease-free survival and OS than double-positive hormone receptor tumors, but they found that single positive hormone receptor tumors are associated with poor survival similar to that of the double negative hormone receptor subtype in Her2− negative BC although there was no difference in survival among the 4 subtypes in patients with Her2− positive disease [22].