More specifically, fine-mapping of all these breast cancer risk loci identified by GWAS found that of 196 strong risk signals, 66 (34%) had a higher risk for ER-positive breast cancer (e.g., CCND1, CHEK2, FGFR2), 29 (15%) with ER-negative disease (e.g., BRCA2, CREBBP, ESR1 risk loci), while the remainder (51%) were associated with similar risks for both ER-positive and ER-negative breast cancer development [81]. This evidence concerns the gene ESR1 and breast cancer.