THY1 and neoplasm: In order to test our hypothesis that primitive hematopoietic cells can survive under conditions commonly found in tumor tissue, we assayed both a total CD34+ population (CD34+) with a majority of hematopoietic progenitors (HPCs) and a rare minority of stem cells and a selected CD34+CD38lowCD133+CD90+CD45RA− population highly enriched in hematopoietic stem cells (HSCs, “stem”) under anoxic, anoxic/aglycemic (ischemia like, “AA”), or physiological conditions (3% O2) for seven days.