Human CLL cells and T cells expand during the first weeks of engraftment in NOG mice but not in BRG mice. (A) Mean human cell expansion in the PB of CLL-PBMC transplanted NOG (n = 26–28; 7 patients in 4 mice each) and BRG (n = 28; 7 patients in 4 mice each) mice two and four weeks after human cell injection (CLL patients #1–#7). CLL cells were characterized as human CD45+, CD19+ and CD5+; human B cells were detected as CD45+, CD5- and CD19+; human T cells were detected as huCD45+, CD19- and CD5+. (B) Mean white blood cell counts (WBC), red blood cell counts (RBC), and platelet (PLT) counts, hemoglobin and hematocrit of non-transplanted age-matched control mice, CLL-PBMC transplanted NOG (n = 26–28; 4 per 7 patients) and BRG mice (n = 28; 4 per 7 patients), analyzed at days 0, 14 and 28 after transplantation (CLL patients #1–#7). (C) Correlation of CLL cell engraftment in the blood with CLL cell engraftment in the spleen (left) or BM (right) of transplanted NOG mice four weeks after transplantation (CLL patients #1–#7) using Pearson correlation calculation.