Leukocyte emigration in CXC chemokine 4- to 5-hours-treated cremasteric postcapillary venules in WT and PI3Kγ^-/- mice. The number of emigrated neutrophils in cremasteric postcapillary venules after intrascrotal injection of (A) MIP-2 and (B) KC in WT and PI3Kγ^-/- mice was determined. These chemokines were injected as a single dose of 1 μg in 200 μL saline (n = 3 to 7 in each group). The control WT mice were injected with 200 μL saline (n = 4). Leukocyte emigration was determined by intravital microscopy at 4, 4.5, and 5 hours after the treatment. **P < .01 as compared with WT or PI3Kγ^-/- mice treated with MIP-2 or KC. Error bars represent means plus or minus SEM.