PECAM1 and neoplasm: To examine in more detail the differences in vessel density and/or changes in vascular permeability in the primary tumor in response to SLC-0111 and sunitinib, we examined whole mount tumor tissue slices, which enable the visualization of vascular structures with increased tissue depth compared to standard IHC, for CD31 expression and the distribution of rhodamine-labeled dextran by immunofluorescence labeling coupled with 3D confocal microscopy.