Based on the semi-quantitative scoring system, normal and hyperplastic mammary glands showed higher ERα immunoexpression (i.e., TS = 8), reflecting their higher expression level of ESR1 mRNA, while the total score for ERα ranged from 4 to 8 for benign CMTs, and from 4 to 7 for malignant tumors, reflecting the decreasing trend in ESR1 gene expression. Here, ESR1 is linked to cancer.