Effect of GM-CSF and G-CSF on CD66b expression and lactoferrin secretion. Neutrophils were incubated with either GM-CSF (A,C) or G-CSF (B,D) at the concentration indicated for 50 min in the absence (white columns) or presence (grey colums) of 1 μM fMLP. fMLP was used as positive control. CD66b levels (A,B) were analyzed by cytofluorimetry and are expressed as MFI. Lactoferrin levels (C,D) were measured in the supernatants. Results are shown as mean ± SEM of five experiments. ANOVA (with Tukey’s post hoc test) and Student t-test. In all four panels, **P < 0.01: + fMLP controls vs. -fMLP controls; *P < 0.05, **P < 0.01, and ***P < 0.0001 as compared with untreated and –fMLP controls or untreated and + fMLP controls.