All androgens stimulate telomere elongation and tamoxifen reverts the positive effects of ADs in DKC-derived BM-MNCs with TERT/TERC mutations. (A) DKC-derived BM-MNCs from patients #1 and #3 (represented by a circle and a square, respectively), were treated for 7 days with vehicle, danazol 150 nM (DN), oxymetholone 1 µM (OX) and nandrolone 5 µM (ND). Next, telomere length was measured via qPCR. One sample t-test was used to determine statistical significance. (B) The same experiment was repeated for patient #4 and telomere length is shown. (C) CFU assay was performed with BM-MNC treated with the following agents: danazol 150 nM (DN), oxymetholone 1 µM (OX), nandrolone 5 µM (ND), tamoxifen 1µM (TAM) and selected combinations, such as DN + TAM, OX + TAM, ND + TAM versus DMSO. The number of colonies was assessed after 7 days and normalized towards the control value. One-way ANOVA was used to determine statistical significance. (D) The same experimental layout of panel C was employed with BM-MNC from patient #4. Mean values ± SD are shown for all experiments. * p < 0.05, *** p < 0.001.