Statistical Analyses

Statistical analyses were performed using GraphPad 5.04 (GraphPad Software, La Jolla, CA) and SPSS 13.0 (IBM SPSS, Inc., Chicago) software. Normality of the data were tested by Kolmogorov–Smirnov test. To test the presence of an outlier, the Grubbs test was used. Mann–Whitney U test (data with non-normal distribution) or unpaired t test (data with normal distribution) was used in case of two groups, as stated in figure legends. In case of more than two groups, data were analyzed by one-way ANOVA using a Newman–Keuls post hoc test. Data are presented as mean±SEM. P values <0.05 were considered to represent statistically significant differences.