Fig. 5. Endothelial markers in cells sprouted from HITA wall during ring assay. Similar to that presented in the Fig. 4B cells isolated from the collagen gel after performing the ring assay also show a clear staining for CEACAM1 (A). Double immunostaining of these cells for CEACAM1 (dark) and VEGF receptor 2 (KDR) (red) demonstrate the colocalization of the VEGFR2 and CEACAM1 in the majority of the cells (B). Nearly all cells are also positive for the endothelial marker TIE2 (C). No specific staining is visible in the control section (D).