Figure 2.

CSA formation by hematopoietic stem cells in the presence of soluble dlk protein. Data are from four experiments: two each with adult BM cells (Sca-1⁺, c-kit⁺, lin^lo/−), and day 14 fetal liver cells (AA4.1⁺, Sca-1⁺, c-kit⁺, lin^lo/−). Results are expressed as the ratio/fold-increase in CSA number for 14 data points each for the four different experiments. Error bars represent SEM. ∗, P = 0.01 comparing dlk vs. none to none vs. control; ∗∗, P = 0.001 comparing dlk vs. control to none vs. control (Student’s t test).