CD34 is a type I transmembrane glycophosphoprotein expressed by hematopoietic stem/progenitor cells (HSCs). CD34 may also stimulates proportions of adult human HSCs to differentiate into full-fledged neurons. This may open new possibilities for a high-yield production of neurons from bone marrow. In tumors, CD34 is found in alveolar soft part sarcoma, preB-ALL (positive in 75%), AML (40%), AML-M7 (most), dermatofibrosarcoma protuberans, gastrointestinal stromal tumors, giant cell fibroblastoma, granulocytic sarcoma, Kaposi