Mast-cell–derived cytokines boost inflammation and emigration of LCs. (A) Two hours after application of either imiquimod or vehicle, RNA was prepared from the ears and analyzed using RT-PCR. Representative of 3 experiments with equivalent results. (B-D) These experiments were performed as described in Figure 1 to examine the role of mast-cell–derived TNF-α (B) and IL-1 (C) on inflammation and emigration of LCs (D). Shown are the means (± SD) from 4 to 5 mice per condition. *P < .01 and **P = .015 versus Kit^+/+.