ESR1 and breast cancer: Stacey et al. genotyped 4,554 breast cancer patients and 17,577 controls using the Illumina Hap300 platform and reported that individuals of European descent with homozygous allele A of rs13387042 SNP on chromosome 2q35 have an estimated 1.44 fold higher risk of estrogen receptor-positive (ER-positive) breast cancer compared to noncarriers, while homozygous allele T of rs3803662 on chromosome 16q12 was associated with 1.64 fold risk of ER-positive breast cancer (Stacey et al. 2007).