IL-23R expression in pediatric B-ALL cells and their normal counterparts. (A) IL-23R surface expression in B-ALL cells from BM patients, as assessed by flow cytometry. Open profile: IL-23R staining; dark profile: isotype matched mAb staining. (B) IL-23R expression on normal early B cells from 12 healthy individuals, by flow cytometry. Left panel: percentage of IL-23R expression in each cell sample. Histograms on the right: IL-23R staining in one representative normal pro-B (top panel), early pre-B (middle panel), and pre-B sample (bottom panel) is shown. Open profile: IL-23R staining; dark profile: isotype-matched mAb staining. (C) Relative quantification of IL-23R mRNA in 29 primary B-ALL samples, compared with their normal counterparts, by real-time PCR. Histograms represent fold differences of IL-23R expression between B-ALL and normal early B cells. The copy number of IL-23R mRNA was normalized on the endogenous reference (GAPDH gene) and expressed relative to a calibrator sample (mean value of 4 normal early B-cell samples) using the 2^−(ΔΔCt) ± SD method.