This discordance may explain the failure rates seen in conventional endocrine adjuvant therapy for patients with DTCs that were ERα negative despite the presence of ERα positive primary tumours.106 Approximately 90% of analysed breast cancer patients with HER3 activation were found to exhibit very low or even no detectable levels of pAKT S473, suggesting that these cells might have fallen into dormancy.61 This evidence concerns the gene ESR1 and breast cancer.