The analysis of the gene expression in all cell lines isolated from the seven mammary tumors revealed the highest expression level of nuclear receptor ERRα in the complex carcinoma 1 (CCa1) sample, while in the rest of the cell lines the levels were lower than in mammary epithelium, with the lowest levels in those cells obtained from the adenomas and simple carcinoma (Fig 5A). This evidence concerns the gene ESRRA and adenoma.