ESR1 and breast cancer: Advanced analysis based on the comparison of the estrogen receptor (ER)-positive and -negative patients with the healthy controls indicated a significant association between rs5743810 allelic frequency and BC risk protection (OR = 0.100, CI = 0.034–0.297, P = 0.00001 for ER+ BC cases; OR = 0.102, CI = 0.033–0.318, P = 0.00001 for ER−BC cases).