Sorting strategy and results of transplantation from fractions of NPM mutant AML. The phenotypes and sorting strategies are displayed for subtypes A-C. Sorted fractions of the leukemias were transplanted into mice. The expression of human CD45, CD33, CD38, and CD34 on bone marrow cells from the mice is displayed in the plots on the right. The nature of the human cells was assessed by quantitative PCR, and the results are indicated by letters adjacent to the plots. M indicates mutated NPM and WT indicates wild-type NPM. (A) The phenotypes of 2 subtype A samples are displayed. The R1 region indicates the gate used for sorting CD34⁺ cells (Ai). Some subtype A samples also have a separate CD34^dim population that is marked by the R2 region (Aii). AML was initiated by the CD34⁻CD38⁺ (Aiii) and CD34⁻CD38⁻ (Av) fractions of sample 3 (subtype A), whereas CD34⁺CD38⁻ cells (Aiv) initiated normal multilineage hematopoiesis. (B) Sample 15 (subtype B) was sorted as indicated (Bi). The CD34⁻CD38⁺ (Bii) and CD34⁺CD38⁺ (Biii) fractions of sample 15 initiated leukemia, whereas CD34⁺CD38⁻ cells (Biv) initiated normal multilineage hematopoiesis. (C) Sample 17 (subtype C) was sorted as indicated (Ci). All fractions of sample 17 initiated AML (Cii-v) though both normal and leukemic cells arose from the CD34⁺CD38⁻ fraction in some mice.