CD38 and acute myeloid leukemia: Present on LSCs in ∼30% of AML. In some cases, CD32+CD34+CD38− cells initiate AML in xenografts, but in others only the CD32− fraction has leukemic potential and is enriched for quiescent LSCs. Absent on normal HSCs. Enriches LSCs in certain CD34− AMLs, but heterogeneous expression patterns limit its reliability as a universal marker