PECAM1 and neoplasm: Meantime, the growth and infiltration of tumor was assessed using IHC staining, which presented less tumor cell proliferation index Ki67 (Fig. 2E&F, *P < 0.05) and lower microvascular density index CD31 (Fig. 2G&H, *P < 0.05) in ApcMin/+;LFA-1−/− mice compared with ApcMin/+ mice.