PECAM1 and neoplasm: It has been established that the tumor periphery exhibits highly active VEGF‐associated angiogenesis, which increases the number and size of vessels by accelerating endothelial cell differentiation/proliferation, primitive vessel generation, vasodilation, and vessel lengthening.24, 25, 26, 27 In our histopathological examinations, these processes manifested as high VEGFR2 and CD31 expression in the tumor periphery.