PECAM1 and neoplasm: In addition, hematoxylin and eosin and immunohistochemical staining revealed that the tumor necrosis ratio was higher in the PGEL group than in the NS, lipiodol, and PVA groups (P < 0.01), and the expression levels of HIF-1α, VEGF, and CD31 decreased after PGEL embolization compared with the lipiodol and PVA treatments.