To confirm whether VM could be detected in tumor tissues obtained from 88 patients with stage IV GC, we used staining for platelet endothelial cell adhesion molecule-1 (CD31) to identify the endothelium in GC tissue sections, as well as periodic acid-Schiff (PAS) stain to identify extracellular matrix-rich channels between tumor cells. Here, PECAM1 is linked to neoplasm.