HSCs and myeloid progenitors are less proliferative in Gli1^null mice. Gli1^wt and Gli1^null mice were injected with BrdU, to mark actively cycling cells, and bone marrow was harvested at 8 hours, labeled with fluorescent antibodies, permeabilized, and labeled with anti-BrdU antibody. Cells were analyzed by flow cytometry. Data are the mean percentage of BrdU-positive cells for each bone marrow fraction in each genotype. A total of 4 mice in each group were analyzed. P values for each group are indicated.