Protein expression in clinical samples was validated via immunohistochemistry (IHC), and survival analysis, immune infiltration assessment, and functional enrichment analyses were performed to explore the biological role of TFF3.<h4>Results</h4>TFF3 was significantly upregulated in BRCA tumor tissues compared with normal tissues (P < 0.001) and was expressed predominantly in malignant cells and tumor-associated macrophages. The gene discussed is TFF3; the disease is neoplasm.