ESR1 and breast cancer: Amcenestrant, camizestrant, and elacestrant (recentlyFDA approved) are orally bioavailable Selective Estrogen ReceptorDegraders (SERDs) that have been evaluated in clinical trials.14,16,28 Capivasertib is an AKT inhibitorthat was approved in combination with fulvestrant for patients withERα+ breast cancer.29ErSO-TFPy was assessed alongside these therapeutic agents in cell cultureusing MCF-7 cells and MCF-7 cells with mutations in ESR1 (coding variants Y537S and D538G) that lead to estrogen-independentgrowth of the cells.