TLR1 was upregulated on about half of the primary human AML samples analyzed. (A) FACS dot plots showing gating of CD34⁺CD38⁻ and CD34⁺CD38⁺ in representative CD34-enriched normal bone marrow (NBM) and primary AML patient samples. (B) Histograms depicting TLR1 expression (purple line: isotype control antibody, red: anti-TLR1 antibody) within CD34⁺CD38⁻ (top histograms) and CD34⁺CD38⁺ (bottom histograms) cells from representative NBM and TLR1-high AML samples, respectively. Geometric mean fluorescence intensity of TLR1 expression in NBM (n = 15) and AML (n = 28) (C) CD34⁺CD38⁻ and (D) CD34⁺CD38⁺ cells. Each dot represents a sample from 1 patient, and horizontal lines indicate mean geometric mean fluorescence intensity for all samples within groups. **P < .01; ****P < .0001.