SCs are quiescent at rest, although the signaling pathways required to maintain quiescence are unknown.

The ability to maintain quiescence is critical for the long-term maintenance of a functional stem cell pool.

However, when and how hematopoietic stem cells acquire their hypoxic state and maintain quiescence has not been fully elucidated.

Low oxygen tension (hypoxia) is commonly thought to be a shared niche characteristic in maintaining quiescence in multiple stem cell types.