PECAM1 and neoplasm: Furthermore, the expression levels of VEGF and CD31 were significantly lower in the tumor slices treated with PGEL than in those treated with lipiodol, NS, and PVA (2.1 ± 1.1% vs. 30.5 ± 7.0% vs. 12.3 ± 2.5% vs. 6.8 ± 1.9% for VEGF and 1.5 ± 0.4% vs. 15.2 ± 1.5% vs. 7.1 ± 0.7% vs. 4.0 ± 0.9% for CD31, respectively, all P < 0.001) (Fig. 5C and D), further suggesting that PGEL achieved the so-called artery-casting embolization, that is, complete occlusion of all levels of arteries, through its good flowability and embolization.