Prevention of IL-8–induced mobilization of progenitor cells by anti–LFA-1 is dose dependent. Mice were pretreated with a single injection of increasing doses of anti–LFA-1 (10, 30, and 100 μg) or saline IP. The following day 30 μg of IL-8 was administered IP 20 minutes before harvesting peripheral blood. Results are expressed as mean (n = 20 for saline and 100 μg anti–LFA-1, and n = 2 for 10 and 30 μg anti–LFA-1).