GR protein expression and ligand binding in xenograft cells. GR protein expression in xenografts was assessed by immunoblot (A). Band intensities were quantified by phosphoimage analysis and normalized to actin. GR expression in all xenografts was also normalized to the CEM-WT cell line. Quantified data revealed a significant deficit in GR protein expression in a single xenograft, ALL-8, compared with CEM-WT cells (P = .04). (B) Saturation curves were plotted for each xenograft following radioligand binding assays. The respective B_max and K_D values are given in Table 2. Specific binding sites per cell were plotted over a range of dexamethasone concentrations. Results shown are cumulative data from 2 independent experiments.