Inhibition of PLC and calcium, but not p44/42 MAPK or PI3K, abrogates RANTES-, fMLP-, and SDF-1–induced LDV-FITC binding to human peripheral blood monocytes. Purified blood monocytes were pretreated with DMSO, U0126 (10 μM), wortmannin (100 nM), U73122 (1 μM), BAPTA-AM (12 μM), or SKF96365 (100 μM) and then stimulated with RANTES (12.5 nM), fMLP (100 nM), or SDF-1 (12.5 nM). LDV-FITC binding was measured by flow cytometry in real time. One of 3 independent experiments is shown.