Aurora kinases are important for growth of tamoxifen resistant cell lines. Parental and tamoxifen resistant T47D cell lines (TR-1 and TR-2) were treated for 5 days with the indicated concentrations of barasertib (A) and parental, fulvestrant and tamoxifen resistant T47D cell lines were treated with JNJ-7706621 (BandC). Cell number was determined by a crystal violet colorimetric assay and expressed as percent of untreated control. The experiments were performed twice with six sample replicates. Representative experiments with mean ± SD are shown. *P < 0.05 for barasertib or JNJ-7706621 treated samples vs. control.