CD38 and acute myeloid leukemia: To test this hypothesis, we used fluorescence-activated cell sorting (FACS) to fractionate primary human AML specimens into CD34+CD38-TMIGD2+ and CD34+CD38-TMIGD2- subpopulations, or CD34+CD38+TMIGD2+ and CD34+CD38+TMIGD2- subpopulations in samples that CD34+CD38- subset was absent (Supplementary Table 3).