ESR1 and breast cancer: Although biomarker changes at the breast cancer tissue level were not statistically significant, trends of increase in cleaved caspase 3 and tumor-infiltrating lymphocytes (TILs) and decrease in Ki-67 and nuclear to cytoplasm ratio of estrogen receptor (ER)-α were observed in the BSE arm, supporting ITC-induced activation of apoptosis and immune function but inhibition of ER-α signaling and cellular proliferation.