A uniform consensus that MHT use is associated with luminal A-like (estrogen receptor (ER)-positive/progesterone receptor (PR)-positive/human epidermal growth factor 2 (HER2)-negative) breast cancer is apparent [15–21], while some studies have indicated a similar association with luminal B-like (ER + /any PR/HER2 + or ER + /PR-/HER2-) subtypes [16, 19–21]. The gene discussed is ESR1; the disease is breast cancer.