Leukemia stem cells (LSCs) have been shown to drive relapse and progression in JMML and include hematopoietic stem and progenitor cells (HSPCs), such as Lin−CD34+CD38− hematopoietic stem (HSCs) and Lin−CD34+CD38+ granulocyte-monocyte progenitor cells (GMPs)14. The gene discussed is CD38; the disease is juvenile myelomonocytic leukemia.