Fig. 3

Nipple duct. a Triple immunofluorescence staining for p63, K8/18, and SMA. p63+ cells (arrows) at the interface of the myoepithelial and luminal layer are negative not only for K8/18 but also for SMA (see also Supplementary Figure 12). b Triple staining for p63(red) and K5 (green), and SMA (pink). Notice that p63+ cells are tethered to the luminal cells (arrows) and show a transition of p63+K5+ cells to K5+ cells in a more luminal position