ESR1 and breast cancer: Molecular BC subtype (45) if luminal like (ER and/or PR positive), HER-2 overexpression (ER and PR negative, HER-2 positive), or triple-negative BC (TNBC) (ER negative, PR negative, and HER-2 negative) and histological BC subtypes, if invasive ductal carcinoma (IDC) or not, were all recorded for correlation analysis.