PECAM1 and neoplasm: Indeed, co‐immunofluorescence staining of ffluc‐expressing DAOY and DAOY‐R tumor sections from NSG mice, with anti‐CD31 and anti‐luciferase antibodies, also revealed a fourfold increase in REST‐dependent colocalization (yellow) of tumor cells (green) with endothelial cells (red) (Fig. 5F).