Homing of p190-B^−/− HPCs. (A) Homing of HPCs to BM. WT and p190-B^−/− BM cells (5 × 10⁶) were injected into lethally irradiated mice. Homing of HPCs, analyzed by CFU assay, was assessed 16 hours after transplantation. Data show the percentage of progenitors (CFU) in the BM divided by CFU activity of input cells (mean ± SEM; n = 3 independent experiments, n = 5 recipients/group). (B) Migration of HPCs. WT and p190-B^−/− LSK FL cells were allowed to migrate toward SDF-1α. Data represent the percentage of migrated progenitors (CFU) divided by CFU activity of input LSK FL cells (mean ± SEM; n = 3 independent experiments). (C) Adhesion of HPCs to fibronectin fragment CH 296 (FN). WT and p190-B^−/− LSK FL cells were allowed to adhere for 1 hour at 37°C to FN. Adherent cells were collected for CFU assays. Data represent the percentage of adherent progenitors (CFU) divided by CFU activity of input cells (mean ± SEM; n = 3 independent experiments).