Fluorescence imaging was used (anti-Cytokeratin 7/Alexa Fluor 488) to locate cancer (HEY) cells, anti-Vimentin (Alexa Fluor 405) to locate fibroblast (HDF) cells, and anti-CD31 (PerCP-eFluor 710) to stain platelet-endothelial cell adhesion molecule-1 expressed on the surface of endothelial (HUVEC) cells. The gene discussed is PECAM1; the disease is cancer.