Rap1 activation is independent of the presence of a functional NADPH oxidase complex. (A) Neutrophils of a p91phox-deficient or a p47-deficient patient were stimulated for 5 minutes with 100 ng/mL TPA or 1 μmol/L fMLP. Rap1 GTP was isolated using GST-Ral-GDS RBD as described in the legend to Fig 1.