Surface marker screening identifies heterogeneity within malignant population. (A-B) Heat map showing (A) MFI or (B) interquantile range (numeric difference between 90% and 10% quantiles: IQR90) of 86 surface markers expressed above isotype levels by at least 10% of the malignant population assayed by flow cytometry. (C) Histograms showing the single-cell distribution of the top 20 most heterogeneously expressed surface markers selected by highest IQR90 within at least 3 patients. Dashed lines display the relevant isotype expression. Histograms are colored by IQR90.