CD34 and Diamond-Blackfan anemia: To evaluate the functional properties of primitive DBA HSCs, we compared the in vivo repopulating ability of BM CD34+ cells from HDs and patients with DBA in immunodeficient Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice (DBA-25, DBA-34, DBA-35, and DBA-36).