S100A4 and breast carcinoma: To explore whether S100A4 is expressed on TAMs, we injected E0771 breast cancer cells into the mammary pads of female S100A4 WT (S100A4WT-EGFP) reporter mice, expressing EGFP under the control of the s100a4 gene promoter.21 25 Then, we collected TAMs and analyzed the immune contexture of S100A4WT-EGFP cells inside the tumor grafts using different markers for immune cell types.