Analysis of early and late engraftment, and differentiation of HSCs and proT2-cells in the thymus of immunodeficient mice. Flow cytometric analysis of CD45 vs HLA-A2 in the thymus at (A) 12 weeks and at (B) 3 weeks, postintrahepatic injection of neonatal NSG mice receiving HSCs, HSCs with proT2-cells, or proT2-cells (n = 5 and n = 12 mice/group, respectively). Human CD45− cells represent cells of host mouse origin. (C) Thymus cellularity in mice receiving HSCs or HSCs with proT2-cells 3 weeks after injection. The results shown are representative of at least 3 independent experiments. Cellularity was calculated based on human CD45+ cells obtained by flow cytometry. *P < .05.