Expression of cell surface NKG2D-L by myeloblastic and monoblastic cells in AML and CMML. (A) FACS analysis of ULBP1 expression by AML peripheral blood cells of 3 patients with AML M2, M4, and M5. Gating of myeloblastic CD45-dim (R1) and monoblastic CD45-intermediate (R2) is shown in top panels, according to side scatter (SSC) and CD45 expression level. Histograms of ULBP1 expression by myeloblastic cells (R1, gray area) and monoblastic cells (R2, black area) are shown in bottom panels. (Thin line) Staining with secondary mAb. (B) Summary of ULBP1, ULBP2, ULBP3, and MICA/B expression levels, defined as MFI-R, by monoblastic and myeloblastic cells in all analyzed AML (n = 66) and CMML (n = 3) patients (for details on individual patients, see Table S1). Horizontal bars show the median values. (P < .001, significant difference in NKG2D-L expression levels by 2 types of leukemic blasts.)