For many years, scientists assumed that blood production took place in the bone marrow. But now, researchers at UCSF are showing it’s also happening in the lungs.

They found hematopoietic stem cells (HSCs) in human lung tissue that make red blood cells, as well as megakaryocytes, which produce the platelets that form blood clots. The findings appear Feb. 27 in the Blood Journal

The work suggests the lungs could be a potent source for life-saving stem cell transplants.