In our previous study, we could show that low AR mRNA was a predictor for shorter survival in breast cancer patients receiving adjuvant chemotherapy.17 The aim of this study was to validate these findings in a defined therapeutic context and to investigate the androgen receptor (AR) and in addition its two isoforms (AR1 and AR2) in breast cancer patients receiving neoadjuvant chemotherapy in two trials: the TECHNO trial (HER2-positive patients) and the PREPARE trial (HER2-positive and -negative patients). This evidence concerns the gene TCF20 and breast cancer.