PECAM1 and neoplasm: IHC staining of tumor tissues showed that protein levels of Ki-67 (a cell proliferation marker), CD31 (an angiogenic marker), N-cadherin and vimentin (two mesenchymal markers) were increased and E-cadherin (an epithelial marker) was decreased in A375CA-TLR4 tumors compared to A375NC tumors (Fig. 4f).