G-CSF inhibits the activation of caspase-9 and -3, but not of caspase-8. Samples of neutrophils incubated in the presence or absence of 10 ng/mL G-CSF were taken at the indicated times, subjected to SDS-PAGE and analyzed on Western blots, stained with antibodies against the indicated caspases. indicates the full-length, inactive caspases and their cleavage products after activation. Equal amounts of cells (1.5 × 10⁶), dissolved in sample buffer, were loaded in each lane. All blots are representative of at least 4 independent experiments.