The composition of peritoneal lavage cells of tumour necrosis factor (TNF)α-treated Lewis (LEW) rats was comparable to that of phosphate-buffered saline (PBS)-treated rats. LEW rats (n = 4) were injected intraperitoneally daily with 1 ml of PBS (top panel) or TNFα (105 U) (bottom panel) for 4 days. After 3 h post the fourth injection, the peritoneal cavity was flushed with PBS and 10 ml of the peritoneal lavage fluid was collected. The cells harvested from the lavage fluid were stained with appropriately labelled anti-CD3 or anti-CD11b/c antibody and analysed by fluorescence-activated cell sorting (FACS). The results of one of the two independent experiments are shown in the figure. Both experiments yielded similar results.