CBX2 is required for both hematopoietic stem and progenitor self-renewal. (A) CFC analysis and subsequent replating of SCR and CBX2 CD34⁺ knockdown cells. (B) CFC colonies were scored on the basis of morphology as CFU-GEMM, BFU-E, and CFU-GM. (C) CFC analysis of transduced CD34⁺ CB cells using 2 distinct shCBX2 hairpin vectors (#1 and #2). (D) Liquid culture of sorted SCR and CBX2 knockdown (#1 and #2) cells. (E) Representative experiment of limiting-dilution LTC-IC analysis of SCR and CBX2 knockdown cells. (F) Representative experiment of single-cell cultures of transduced CD34⁺CD38⁻ cells. Wells without cells were annotated as apoptosis, wells with 1 cell as quiescent, and wells with >1 cell as proliferation. (G) Annexin V staining of transduced CD34⁺ cells after 3 days of liquid culture (n = 2).