To assess the relevance of these findings in breastcancer cells, we conducted in vitro experiments using TNBC cells.We used MDA-MB-231 (human TNBC cells), 4T1 (murine TNBC cells), andMCF-7 (human ER+, PR+, and HER2-breast cancer cells) cells to determinethe effects of Dox and ActD alone on cell viability and compared themto other commonly used chemotherapy drugs. This evidence concerns the gene PGR and breast cancer.