GAS6/AXL expression is highly increased in primitive AML patient cells. (A) qRT-PCR results for AXL and GAS6 transcript levels in unpurified (FH/NH₄CL) cells, CD34⁺ stem/progenitor cells, and CD34⁻ cells from patients with AML (CD34⁺ cells from 18 samples and CD34⁻ from 6 samples). (B) qRT-PCR results for AXL and GAS6 transcript levels in stem cell–enriched CD34⁺CD38⁻, CD34⁺CD38⁺ progenitor and CD34⁻ mature cells from patients with AML. (C) Dot plot of AXL vs GAS6 transcript levels in MLL (n = 10) and non-MLL (n = 6) primary AML samples. (D) RNA-seq analysis of transcript levels of AXL and GAS6 in MLL (n = 9) and non-MLL (n = 296) samples from patients with AML obtained from the Beat AML program. (E-F) FACS graphs of AXL-APC⁺ surface staining in CD34⁺ AML and NBM cells from cohort 1 (left panel: AML, n = 10 and NBM, n = 3) and representative samples from cohort 2 (right panel: AML, n = 12 and NBM, n = 6) (E) with corresponding quantification of mean fluorescence intensity in all samples from both cohorts (F). (G-H) FACS graphs of AXL-APC⁺ staining in CD34⁺CD38⁻ AML and NBM cells from cohort 1 (AML, n = 10 and NBM, n = 3) (G), with corresponding quantification of mean fluorescence intensity (H). The P values were calculated using a 2-tailed, unpaired Student t test or 1-way ANOVA with Tukey’s post hoc correction for multiple comparisons.