Common lymphoid progenitors express Hmgb3. (A) Isolation of GFP⁺ and GFP^– common lymphoid progenitors by flow cytometry. Upper: Lin^– bone marrow isolated from Hmgb3-KI mice. Middle: c-kit and Sca-1 expression in Hmgb3-KI Lin^– bone marrow (left). Cells positive for c-kit and Sca-1 were selected based on isotype staining of littermate control Lin^– bone marrow cells (right). Lower: IL-7Rα and GFP profiles of c-kit⁺/Sca-1⁺ cells (left). Cells were separated into IL-7Rα⁺ and GFP^+/– populations based on isotype staining of littermate control Lin^– c-kit⁺, Sca-1⁺ bone marrow cells (Right). (B) Mean CFU–pre-B cell frequency in GFP^– (n = 8, 66 colonies counted) and GFP⁺ (n = 7, 294 colonies counted) CLP populations. Values were determined by scoring pre–B cell colonies per 500 cells cultured. P values were determined by Student t test.