ESR1 and breast cancer: Different studies have compared SOX10 expression among different subtypes of BC using different study designs and methodologies and the expression was higher in TNBC and ER-negative (ER-) subtypes as compared to ER-positive (ER+) and HER-2 positive (HER-2+) subtypes [5,7,9,13,14,20,21,29] (summarized in Table 3).