We distinguished four different sets of genes dysregulated by ERα: Primary and overall transcriptional effects elicited by stimulating the ER positive MCF-7 breast cancer cell line with estradiol [44], and effects elicited after stimulating the ER negative MDA-MB-231 breast cancer cell line with estradiol with and without re-expressing ERα [45]. This evidence concerns the gene ESR1 and breast carcinoma.