Repeated isolation procedures revealed that it was possible to isolate approximately 0.45×106 CD31-positive ECs from one heart, approximately 3×106 CD31-positive ECs from one lung, approximately 0.025×106 CD31-positive ECs from one repair blastema and approximately 0.1×106 CD31-positive ECs from one tumor (Figure 3A, B). The gene discussed is PECAM1; the disease is neoplasm.