Weill Cornell Medicine Mar 10 2025 A single molecular switch is essential for blood stem cells to enter an activated, regenerative state in which they produce new blood cells, according to a preclinical study led by Weill Cornell Medicine investigators. The discovery could lead to more effective bone marrow transplants and gene therapies. Stem cells are immature cells that have a basic regenerative role in virtually all tissues. They normally exist in a quiescent, slowly dividing state, but