What cell type is identified by the CD34 marker?

The CD34 marker is primarily associated with hematopoietic stem cells, which are the progenitor cells capable of giving rise to all blood cell types. In the hematopoietic system, CD34 serves as a key marker for identifying these stem cells and their early progeny in the bone marrow and peripheral blood. CD34+ cells play a vital role in the process of hematopoiesis, making it essential for regenerative medicine applications, including stem cell transplantation.

This marker is often used in clinical settings to isolate hematopoietic stem cells for various therapies, capturing their ability to self-renew and differentiate into various cell types, such as red blood cells, white blood cells, and platelets. The expression of CD34 is also a defining feature in distinguishing stem cells from more differentiated blood cells, which do not express this marker. The other cell types mentioned—immature lymphocytes, B cells, and T cells—have more specific markers and are usually differentiated through additional surface proteins, unlike hematopoietic stem cells, for which CD34 is a hallmark marker.