primitive lymphoid progenitors. tor Tissue Phenotypea Lin 3− HSC BM, blood Lin− c-KitHi Sca1Hi IL-7Rα− CD27− Multipo 3+ MPP BM, blood thy Lin− c-KitHi Sca1Hi IL-7Rα− CD27+ Multipotent 1.1− LSP BM Lin− c-KitHi Sca1Hi IL-7Rα− Thy1.1− T, (w)B 3+ CD62L+ BM, blood Lin− c-KitHi Sca1Hi IL-7Rα− CD44+ T, B 3+ ELP BM, blood Lin− c-KitHi Sca1Hi IL-7Rα− CD44+ CD27+ RAG-1+/− B, T, NK, ( BM Lin− c-KitLo Sca1Lo IL-7Rα+/− Flt3+ CD27+ RAG-1+ B, T, NK BM Lin− c-KitLo Sca1Lo IL-7Rα+ Flt3+ AA4.1+ B, n A BM B220+ CD19− CD43+ CD24−/Lo BP-1− B, NK, BM, blood, thy Lin− B220+ CD19− IL-7Rα+ c-Kit− Sca1+ pTα+ T, B Thymus Lin− c-KitHi Sca1Hi IL-7Rα−/Lo CD25− T, B, N Thymus Lin− CD25− c-KitHi IL-7Rα− CD44Hi Thy1− CD24− T, NK Thymus Lin− CD25− c-KitHi IL-7Rα− CD44Hi Thy1− CD24Lo T, NK Thymus Lin− CD25− c-KitLo IL-7Rα− CD44Hi Thy1−/+ CD24+ T, B Thymus Lin− CD25− c-Kit− IL-7Rα− CD44Hi Thy1+ CD24+ T, B Thymus Lin− CD25− c-KitLo/− IL-7Rα+ CD44HiThy1−/+ CD24− T Thymus Lin− CD25+ c-Kit+ IL-7Rα−/+ CD44+ Thy1−/Lo T, DC