Superoxide-production of ARHGAP25-silenced PLB-985 cells. Superoxide production of PLB cells transfected with ARHGAP25 specific (●) or control shRNA (○) was stimulated with pooled human serum-opsonized zymosan (mean ± SEM of 13 separate experiments; A), with heat-inactivated serum (mean + SEM of 8 separate experiments; B), and with 0.1μM phorbol ester (mean + SEM of 9 separate experiments; C). RLU indicates relative fluorescence unit; and OD, optical density.