ESR1 and breast cancer: In a recent study, researchers at MD Anderson Cancer Center (MDACC) reported a similar incidence of BRCA1/2 mutations in patients with ER low-positive/PR low-positive/HER-2 neu negative tumors and patients with triple-negative breast cancer, suggesting that genetic counseling and BRCA testing should also be offered to patients who have hormone receptor–low-positive breast cancers [32].