In this regard, transcriptomic analysis reveals that E2 increases by 2-7 times the mRNA level of some glycolytic (HK-I and -II, PFK-2 and LDH-A) and mitochondrial (ND1 and COX-IV) enzymes in MCF-7 and T47D ER+-breast cancer cells (10, 11). This evidence concerns the gene ESR1 and breast cancer.