Human haematopoietic progenitor cells display the cellsurface glycophosphoprotein CD34, which can be utilisedto identify blast cells. According to published research,CD34, a marker for vascular endothelial cells, is extremelysensitive to angiosarcomas and Kaposi’s sarcomas.Furthermore, soft tissue tumours such gastrointestinalstromal tumours (GIST) express CD34.