Figure 1: Principles of gating. The whole population of bone marrow cells was gated in the FSC/SSC cytogram (P1), and then the non-lineage markerexpressing cells were gated in the P1-restricted cytogram (P2). The lin- cells from the P2 gate were divided into three populations: P3-lin-/Sca-1+/c-kitcells (the G1 group); P4-lin-/Sca-1+/c-kit+ cells (G2); and P5-lin-/Sca-1-/c-kit+ cells (G3).