Cancer‐associated fibroblast markers (neprolysin, matrix metalloproteinase 9 [MMP9], tenascin‐C), markers of epithelial‐mesenchymal transition, a prerequisite to metastasis (TGFβ1, cadherin 1/E‐cadherin, fibronectin, vimentin, cytokeratin 8, and cytokeratin 18) and breast cancer stem cell markers (CD44, CD133) were also detected in all NAF samples. Here, KRT18 is linked to breast cancer.