Cited2 deficiency results in impaired reconstitution of multiple lineages in primary and secondary transplantations. (A) Fetal liver cells (10⁶) from each of Cited2^−/− (n = 3) and Cited2^+/+ (n = 3) embryos were injected via tail vein into lethally irradiated congenic recipient mice, and the peripheral blood reconstitution of T-lymphoid, B-lymphoid, and myeloid cells was analyzed 8 months after transplantation. The long-term reconstitution of T-lymphoid, B-lymphoid, and myeloid lineages was impaired as shown by significantly decreased absolute number of donor-derived cells of each lineage (P < .01) in Cited2^−/− mice that underwent transplantation. Donor chimerism was determined as: [%CD45.2⁺CD3⁺/%CD3⁺] × 100, [%CD45.2⁺B220⁺/%B220⁺] × 100, [%CD45.2⁺Mac-1⁺/%Mac-1⁺] × 100, [%CD45.2⁺Gr-1⁺/%Gr-1⁺] × 100. (B) Secondary transplantation was performed 8 months after the primary transplantation. Bone marrow cells (10⁷) were harvested from primary transplants and transplanted into recipient mice after irradiation (9 Gy). Significantly decreased numbers of donor-derived T-lymphoid, B-lymphoid, and myeloid cells were observed in Cited2^−/− mice that underwent transplantation (P < .01).