GPI-80 expression highly purifies human cord blood-derived primitive CD34-negative hematopoietic stem cells.

To the editor: We identified very primitive CD34-negative (CD34−) severe combined immunodeficiency–repopulating cells (SRCs) in human cord blood (CB) using the intrabone marrow injection method[1][1] and provided a new concept for the hierarchy in the human hematopoietic stem cell (HSC)