In AML-4, there were no copy number abnormalities, thus 40% of cells in immunophenotypically defined (CD34+CD38–) LSC compartment harbored one mutated TP53 allele, while all cells in non-LSC (CD34+CD38+) compartment were heterozygous for TP53 mutation, suggesting clonal selection of mutated LSCs. The gene discussed is CD38; the disease is acute myeloid leukemia.