a, Human AML cells show heterogeneous surface expression of the NKG2D ligands MICA, MICB, ULBP1 and ULBP2, ULBP5 or ULBP6. Flow cytometry analysis with antibodies against human MICA, MICB, ULBP1 or ULBP2, ULBP5 or ULBP6 in primary AML samples from n = 62 patients. b–e, Surface expression of NKG2DLs distinguishes leukaemic subpopulations with different morphology, clonogenic capacity and molecular characteristics. AML cells stained with conjugated NKG2D–Fc chimeric protein were sorted according to expression of NKG2DLs and analysed by May–Grünwald–Giemsa stainings (b) and forward and sideward flow cytometry plots (c). When compared to corresponding NKG2DL− (NKG2DLneg) AML cells isolated from the same patient, NKG2DL+ (NKG2DLpos) AML subpopulations display more-mature morphology, irrespective of CD34 expression. d, Furthermore, colony-forming assays indicate intermediate clonogenicity in AML cells with intermediate surface expression of NKG2DLs (NKG2DLinterm AML cells; left, representative plot depicting sorting strategy, no. 37; right, summarized results from technical triplicate analyses performed with n = 3 cases of AML). Centre values represent mean, error bars represent s.d.; one-way ANOVA was used for statistical analysis. e, GSEA analyses reveal enriched haematopoietic stem cell and suppressed progenitor signatures in NKG2DL− compared to NKG2DL+ AML cells (no. 1, 6, 7, 8 and 12).