In addition to cytometric assays, we also carried out Western immunoblot analysis of the expression of Bax, caspase 7 and 9, and p53 in MCF-7 and MDA-MB-231 breast cancer cells treated (for 24 h) with the tested selenoesters (EDAG-1 and EDAG-8) and the reference agent (cisplatin)m which were applied at two concentrations (0.5 and 1 μM) to validate the results obtained by flow cytometry. This evidence concerns the gene TP53 and breast carcinoma.