Rebbeck et al. confirmed the role of the MAP3K1 rs889312 SNP in breast cancer susceptibility in African-American patients, and revealed that MAP3K1 genotypes conferred their effects in primarily ER+ and PR+ tumors, and that patients carrying the AC or CC genotypes had a noticeably higher breast cancer risk than those carrying the AA genotype [10]. The gene discussed is ESR1; the disease is breast carcinoma.