Caspase-9 activation in GSD-Ib neutrophils. Peritoneal neutrophils were isolated from 6- to 7-week-old unaffected (+/+) and GSD-Ib (−/−) mice during thioglycollate-elicited peritonitis. (A) Immunofluorescence of active caspase-9 staining (green fluorescence) and Hoechst 33342 nuclei staining (blue fluorescence), magnification ×400. (B) Quantification of caspase-9–positive neutrophils in unaffected and GSD-Ib mice. Data represent the means (± SEM) of 3 independent experiments. ***P < .001.