G-CSF can delay but not prevent apoptotic death of G6pc3^−/− BM neutrophils cultured in vitro. The annexin V–depleted BM neutrophils were isolated from 6- to 8-week-old unaffected (+/+, ○, ●) and G6pc3^−/− (−/−, Δ, ▴) littermates as described in “Neutrophil isolation.” (A) Neutrophil viability. (B) Representative flow cytometric analysis of neutrophil survival. (C) Quantitative analysis of neutrophil survival in untreated wild-type (○, ●) and G6pc3^−/− (Δ, ▴) mice in the absence (○, Δ) or presence (●, ▴) of G-CSF. Data are the mean ± SEM of 4 independent experiments. (D) Flow cytometric analysis of G-CSFR. (E) Western blot analysis of protein extracts of neutrophils using antibodies against GRP78, PDI, Bax, Smac/Diablo, or β-actin. Each lane contains 50 μg protein. (F) Quantitative flow cytometric analysis of p-Akt in neutrophils of untreated wild-type (○, ●) and G6pc3^−/− (Δ, ▴) mice in the absence (○, Δ) or presence (●, ▴) of G-CSF. Data are the mean ± SEM of 3 independent experiments. **P < .005. *P < .05.