Composite FACS images of PBMNCs stained with antihuman CD14 FITC and anti-CD16 PE to determine the proportion of CD16++/CD14+ (region 1) to total CD14++ monocytes (region 2) in blood derived from adults (6), and from term (3) and preterm neonatal individuals (6). The proportion of CD14+CD16++ to CD14++ cells is as follows: adults, 23% ± 19%; term, 19% ± 4%; preterm, 4% ± 2%. (P < .05 v adult.)