CD90/Thy1 negativity is often used to enrich LSCs, particularly to distinguish from healthy HSCs18 with more AML-driver mutations found in LSCs sorted from 3 patients at adverse risk and 1 at intermediate risk by CD34+CD38–CD90– as compared to the CD34+CD38–CD90+ sorted cells.11 This evidence concerns the gene CD38 and acute myeloid leukemia.