PBMCs from patients with AML M4.

(A) Relative expression levels of TRAIL-R1-R4 mRNA in PBMCs derived from AML patients and cord blood CD34⁺ cells. Relative TRAIL-R1-R4 mRNA expression was assessed by multiple relative RT-PCR as described in “Patients, materials, and methods.” The results are expressed as mean ± SD of 6 experiments. (B) Surface expression of TRAIL–R1-R4 on PBMCs derived from AML patients. Expression of TRAIL–R1-R4 on the PBMCs from Pt 1 (M4) and Pt 4 (M1) was assessed by flow cytometry after cell surface staining with polyclonal antibodies against TRAIL-R1, -R2, -R3, or -R4 (shaded histograms). Open histograms show the staining with control goat IgG.