Normal microbial killing by GPS neutrophils. Killing of S aureus (A), E coli (B), C albicans (C), and A fumigatus (D) was assessed with neutrophils from healthy controls and patients with GPS. The microbial viability was quantified as colony-forming units and expressed as a percentage relative to the colony-forming units at the start of the assay. Results are means ± SEM, n = 3-10. An unpaired, 2-tailed t test was used. **P < .01.