Nectin-4 expression in breast carcinoma. A: Normal breast epithelium does not express Nectin-4. No expression was detected in luminal, myoepithelial and stromal cells. Nectin-4 expression was found prominently in ductal carcinoma. Bar 50 μm. Magnification: × 200. B: Both invasive (black arrow) and in situ (white arrow) components of ductal carcinoma are immunostained by Nectin-4. C: Immunofluorescence analysis revealed that Nectin-4 expression is cytoplasmic (arrowhead) and junctional (arrow). Similar results were obtained with both mAbs Magnification: × 640.