Phenotype of human CD19⁺ B cells detected in the marrow of a NOD-SCID mouse transplanted with human CD34⁺- CD19⁻CD10⁻ cord blood cells. In this representative experiment, NOD-mice were injected with 60,000 CD34⁺CD19⁻CD10⁻ cord blood cells. Six weeks later, mice were killed and the bone marrow cells were labeled with a panel of MoAbs recognizing human antigens. Analysis was performed in the morphologic gate defined in (A), which includes all human lymphoid cells. Quadrant limits were set as defined in Fig 1 using PE-labeled (B) and FITC-labeled (C) control antibodies.