Fig. 4

Negative staining for von Willebrand factor, CD31, and p63 in the cystic spaces of IMPC areas in the canine mammary gland. Superresolution images of the nuclear envelope markers Lamin B1/B2 (green), von Willebrand factor (a), CD31 (b), and p63 (c) (red); nuclei were stained with Hoechst (blue). Note that the staining is negative for endothelial and lymphatic cell markers (CD31 or von Willebrand factor) in micropapillary areas. Staining for the myoepithelial cell marker p63 is negative in IMPC and positive in the control sample of a normal mammary gland (d). The merged images show the overlapping signals. Representative images from n = 4 discrete primary tumor cases are shown, and ten images were acquired from in situ and invasive areas in each case. Scale bars = 20 μm