Statistical Analyses
Statistical analyses of protein expression, ELISA data, and filter trap assays were performed by ANOVA with Tukey's honest significant difference post-hoc test applied to significant main effects or interactions (Statistica 6.0, StatSoft, Tulsa, Oklahoma, United States). In cases of positively skewed data distribution, log10(x + 0.5) transformation was applied to the raw data before submitting them to ANOVA.