Interestingly, evaluating ZNF217 expression levels in the primary breast tumor of ER+/HER2-/LN0 breast cancer patients treated by adjuvant ET led to the identification of poorer responders prone to earlier relapse, while in ER+/HER2-/LN0 breast cancer patients who did not receive any treatment the association between ZNF217 expression and RFS was not significant. This evidence concerns the gene ESR1 and breast carcinoma.