PECAM1 and neoplasm: While expression of the tight-junction gene CLDN5 was similar in Pe1 ECs and Co1 ECs (Figure 5B and Figure 6, A and B), some adherens junction mRNAs, including VE-cadherin (encoded by CDH5) and CD31, were upregulated in ECs in the tumor core compared with peripheral ECs (Figure 5B).