ESR1 and neoplasm: In the multivariate logistic analysis performed by selecting stromal ER positivity, subtype, Ki67 index, age, and tumor diameter as covariates for predicting pCR, stromal ER positivity (OR: 3.059; 95% CI [1.947–4.807]; p < 0.001), intrinsic subtype (OR: 1.477; 95% CI [1.102–1.980]; p = 0.009), and Ki67 index (OR: 1.028; 95% CI [1.104–1.041]; p < 0.001) were found to be independent factors (Table 2).