PECAM1 and gastric cancer: In a cell line characterized by rapid proliferation, scirrhous gastric cancer (SGC)—which was subcutaneously engrafted together with BM-MSCs into nude mice—BM-MSCs significantly increased GC neovascularization, especially after Helicobacter pylori exposure; this was shown by the increased expression of CD31—a platelet-endothelial cell adhesion molecule used as a marker of angiogenesis—and the neuron-glial antigen 2 (NG2) proteoglycan, which stimulates tumor vascularization by mediating pericyte endothelial cell interactions.