PECAM1 and neoplasm: The VRM map revealed a ring pattern around the tumor, with high vascular reactivity index value (27%) within the tumor, indicating the presence of new immature blood vessels, Pathological evaluation of samples obtained from this tumor indicated high proliferation index, as demonstrated by Ki67 immunohistochemical staining (Figure 2F); and high vascular density, as shown by anti CD31 immunostaining of endothelial cells (Figure 2G), with only a few SMA positive vessels (Figure 2H).