PECAM1 and cancer: Analogous geometries can beassembled and analyzed using any other cell types (e.g. cancer cells and stromalcells [45]).Cultures that contain more than two distinct cell types (e.g., cancer, stromal,and endothelial cells) can be assembled in the same manner, provided that eachcell can be traced using a distinct fluorescent reporter, or cell specificmarker (e.g., CD31 for endothelial cells).