Phenotypic analysis of engrafted NOD/SCID bone marrow. Bone marrow cells removed from NOD/SCID mice that had been engrafted with sorted T-ALL cells were analyzed in more detail using additional lineage markers. Cells were initially gated on the basis of low forward and side scatter (A), then CD45⁺ cells were gated (B) and the expression of the lymphoid and myeloid antigens on these gated cells was investigated. The peaks representing specific lymphoid and myeloid antibodies are shown in black, and isotype controls are represented as translucent peaks on the overlay histograms. The figure shows the immunophenotype of cells removed from a NOD/SCID mouse inoculated with cells from patient 6. The engrafted ALL cells were found to express CD2, CD4, and CD7. CD8 cells were also detected in this sample, which is consistent with the high expression of CD8 in the diagnostic biopsy sample from this patient.