ESR1 and triple-negative breast carcinoma: This is in line with the data published by Islami et al. showing that in a subset of three studies that adjusted for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2/neu) status, having ever breastfed showed a stronger inverse association with triple-negative breast cancer (odds ratio (OR) 0.78; 95% CI 0.66–0.91) among parous women [41].