(A) Representative FACS profiles of marrow cells from individual NOD/SCID mice transplanted 8 weeks previously with cells deriving from 3.5 × 10⁴ CD34⁺ CB cells after a 10-week expansion in stroma-free cultures containing IL-6, SCF, FL and MGDF. From top to bottom: isotype control and (a) a nonengrafted mouse. Human CD45/CD34 and CD45/CD19 in the BM cells of a mouse transplanted with 1/8, 1/25, and 1/70 of the cell progeny deriving from 3.5 × 10⁴ initial CD34⁺ cells. CD45/CD34 and CD45/CD19 analysis was performed on total BM cells. (B) Multilineage engraftment in the BM of a representative mouse transplanted with week 10 expanded cells (deriving from 2 × 10⁴ initial CD34⁺ cells). Analysis of lineage markers (CD45/CD34, CD19, CD41, and CD13/CD33) was performed on cells comprised within the CD45 gate. Analysis of GpA/CD71 cells was performed on total BM cells.