PECAM1 and neoplasm: Furthermore, flow cytometry analysis revealed that vascular cells (CD45− EpCAM− CD31+) express both α5 and β1 integrins, while other stromal cells (CD45− EpCAM− CD31−) express only β1 integrin (Fig. S6), suggesting that vascular cells could also be a target of ANGPTL2 signaling in the tRCC tumor microenvironment.