TGFB1 and congenital secretory chloride diarrhea 1: In liver-biopsy CLD specimens, the amount of TGF-β1 mRNA is positively correlated with that of type I collagen mRNA.447 TGF-β1 mRNA concentrations in the liver positively correlate with serum concentrations of peptide fragments of type III collagen and the histological activity of the liver disease.