Immunohistochemical staining revealed the expression of Ki-67 in tumour cell nuclei (Figures 6(a) and 6(b)), CD31 in endothelial cells of the tumour, and vascular endothelial growth factor (VEGF) in tumour cell cytoplasm (Figures 6(c) and 6(d)). Here, PECAM1 is linked to neoplasm.