SMAD3 and kidney disorder: No significant changes were observed in proteinuria (1.08 ± 0.64 vs. 1.28 ± 1.27 g/24 h) or serum creatinine levels (0.109 ± 0.03 vs. 0.164 ± 0.104 mg/dL, on D0 and D21, respectively) in the 129.Smad3−/− mice 24 h after anti-GBM serum challenge; however, significant changes in proteinuria (D0, 0.90 ± 0.36; D14, 8.99 ± 5.95; D21, 8.42 ± 5.54 g/24 h, p < 0.0001) and increased serum creatinine levels (D0, 0.121 ± 0.04; D14, 0.288 ± 0.123 mg/dL, p = 0.018) were observed in the WT control mice, indicating severe renal disease.