Data are expressed as the mean ± SEM. Differences between two experimental groups were assessed using the Student’s t-test, and those among more than three experimental groups were assessed by one-way ANOVA with Tukey’s HSD post hoc test. Differences in the proteinuria-free survival time and the survival time of the groups were analyzed using the log-rank test and the Cox proportional hazard model. P-values of < 0.05 were considered statistically significant. All statistical analyses were performed using the JMP software (version 11; SAS Institute Inc., Cary, NC).