COL1A1 and fibrosis: Although the serum creatinine levels in the HPi + LCas and HPi + MCas groups were not statistically different, the moderate dietary casein levels also suppressed mRNA expression for Havcr1, Tnf, Icam1, Tgfb1, Col1a1, and Masson-based fibrosis in the kidney in comparison with those in the HPi + LCas group (P < 0.001 for Masson staining; P < 0.01 for mRNA analyses; P > 0.05 for serum creatinine; Fig. 1a,b, and Table 1).