ESR1 and breast cancer: According to molecular classification of breast cancer, more CHD5-positive breast cancers belonged to the luminal A subtype (ER+ and/or PR+, HER2-), while more CHD5-negative tumors belonged to the luminal B (ER+ and/or PR+, HER2+), HER2 (ER-, PR-, HER2+), or the triple negative subtype (ER-, PR-, HER2-) (P < 0.001).