AR and breast cancer: In the I-SPY 1 dataset, AR expression was found to be significantly lower in TNBC (i.e. HR−/HER2−) than HR+/HER2− and HER2+ disease (Fig. 1a, p < 0.00001), as expected and concordant with previous literature.9 When evaluated by intrinsic subtype, AR expression was the lowest in basal breast cancer (Fig. 1b, p < 0.00001).