A typical circulating endothelial cell detected with the HD-CEC assay. The panels show a) a DAPI positive, large nucleus surrounded by numerous smaller nuclei of WBCs, b) CD45 positivity on white blood cells only, c) a CD146 positive cytoplasm, and d) von Willebrand factor positive cytoplasm with a staining pattern that is distinct from the CD146. Notice that surrounding platelets are also positive for vWF. Panel e) is the composite image of DAPI, CD45 and CD146 and panel f) is the composite image of DAPI, CD45 and vWF.