Phenotypic and genetic evaluation of CMML xenografts. (A) Comparison of human CD45 (hCD45) chimerism in the BM, spleen, and PB of NSGS-recipient mice. Recipient NSGS mice were engrafted with purified BM CD34⁺ cells, BM MNCs, or PB MNCs (the mean value is represented by the line inside the box ± standard deviation represented by lines above and below the box; *P < .05; number of individual mice is represented in the figure). (B) Spleen weights of NSGS-recipient mice engrafted with purified BM CD34⁺ cells, BM MNCs, or PB MNCs from CMML patients and control mice (left). NSGS-recipient mice that were injected with <0.2 million hCD34⁺ cells and showed no evidence of engraftment of hCD45⁺ cells at day 201 posttransplant were used as controls (the mean value is represented by the line inside the box ± standard deviation represented by lines above and below the box; *P < .05, **P < .01; number of individual mice is represented in the figure). Representative photographs of spleens from mice injected with BM CD34⁺ cells and control mice are shown on the right (each photograph was taken with an inch ruler). (C) Spleen weights of NSGS-recipient mice engrafted with CD34⁺ cells from CMML patients with (n = 4) or without (n = 4) splenomegaly (the mean value is represented by the line inside the box ± standard deviation represented by lines above and below the box; **P < .01). (D) Variant allele frequency (VAF) of genomic DNA from BM MNCs from CMML patients (x-axis) and corresponding purified hCD45⁺ cells from engrafted NSGS mice at end stage (y-axis). The correlation of patient and xenograft VAF is measured in each case by the coefficient of determination (R²) and P values calculated by PRISM 6.