PGR and breast cancer: Taken together our results indicate that while MCF-7-Control cells display molecular profiles characteristic of the luminal A subtype of breast cancer (ER-positive, PR-positive and HER-2/neu-negative) [37, 38], MCF-7-Snail have acquired profiles characteristic of the triple-negative (ER-negative, PR-negative, HER-2/neu-negative), breast cancer subtype.