It has been reported that CD109 is over-expressed in tumor vasculature [24], and in this study we observed that all endothelial colonies from healthy subjects and from 10 cancer patients were positive for CD31, CD146, CD34 and VEGFR-2 and negative for CD45, while CD109 was positive on 1/9 endothelial cultures from healthy subject (11%) and on 5/10 (50%) endothelial cultures from cancer patients. The gene discussed is PTPRC; the disease is neoplasm.