S100A2 expression in PanIN and invasive ductal carcinoma (IDC) cells is higher than that in normal ductal cells, pancreatitis-affected epithelial cells (PAEs), and IPMNs and is upregulated in IDC cells from poorly differentiated adenocarcinoma compared to IDC cells from normally differentiated adenocarcinoma (36). This evidence concerns the gene S100A2 and invasive ductal breast carcinoma.