Human skin mast cells at rest were stained with PE-labeled anti-gp130 or anti-IL-6Rα and analyzed by flow cytometry (A, C). Significance was determined by analysis of Mean Fluorescence Intensity (MFI) (B, C). The effect of IL-10 on gp130 expression was determined by culturing human skin mast cells with IL-10 (10 ng/ml) for 24 h, and analyzing gp130 gene expression by quantitative real-time PCR (E) and surface expression by flow cytometry (F). Bars represent mean ± S.E.M. of values from 3 separate experiments with mast cells from different donors. Significance was determined with Student’s t-test. *, p<0.05 and **, p<0.01.