ALLN, PDTC, or NaSal, but not dexamethasone, prevents the IL-4–induced increase in P-selectin protein in HUVEC. The cells were pretreated with the indicated pharmacological agent and then incubated in the presence or absence of IL-4 as in Fig 1A. The cells were then lysed in buffer containing Triton X-100, and the amount of P-selectin in the lysate was measured by ELISA. The data represent the mean ± SD of triplicate determinations and are representative of three experiments. *, Significantly different from the IL-4–treated group (P < .01).