Induction or prevention of apoptosis by cytokines as measured by analysis of CD16 expression. Flow cytometric analysis of DNA content using the FITC-labeled anti-CD16 MoAb. PMN freshly isolated from the circulation (dotted line) were stimulated for 2, 6, or 22 hours with 300 U/mL TNF-, 300 U/mL GM-CSF, or left untreated (control), respectively. Numbers indicate the cells with low CD16 expression in percent of total cell number. Results are representative of three independent experiments.