The end points were epidermal growth factor receptor ( EGFR ; marker of epithelial activation ) and the biomarkers of EMT : reticular basement membrane ( Rbm ) fragmentation ( `` hallmark '' structural marker ) , matrix metalloproteinase-9 ( MMP-9 ) cell expression , and S100A4 expression in basal epithelial and Rbm cells ( mesenchymal transition markers ) .