To examine if endocrine therapy can eliminate the prognostic effect of TLK2 OE, we analysed the gene expression data set by Loi et al. 20 for 263 ER+ breast tumours treated with adjuvant tamoxifen monotherapy, which revealed a significantly worse recurrence-free survival of patients with TLK2-high tumours (based on log-rank test, P=0.001). This evidence concerns the gene ESR1 and neoplasm.