CSF1R is expressed not on the bulk leukemia population in primary AML patient samples but on a small subpopulation of supportive cells. (A) Schematic diagram of CyTOF analysis to profile CSF1R^hi cells in primary AML patient samples. (B) Percentage of CSF1R^hi cells in primary samples from patients with AML (n = 66) and healthy donors (HD) (n = 11). (C) Correlation of the proportion of CSF1R^hi cells in primary AML patient samples with the sample’s response to GW-2580. Significance determined by Spearman rank test. (D-E) Representative CyTOF plots of CSF1R expression in primary AML patient samples that show (D) sensitivity and (E) resistance to GW-2580. (F-G) Violin plots of expression intensity of other cell-surface markers in CSF1R^hi cells from (F) AML patient and (G) healthy donor samples. (H) Cell-surface marker expression (median arcsinh) in CSF1R^hi cells for AML patient and healthy donor samples. (I) t-SNE analysis of CSF1R expression in cells isolated from primary AML patient sample (n = 66). (J) t-SNE analysis with labeled CSF1R^hi and non-CSF1R^hi cells in primary AML patient samples (n = 66) and healthy donors (n = 11).