COL1A1 and Hepatic fibrosis: In agreement with the increased liver fibrosis in TCDD-treated TiparpH532A mice, we observed higher gene expression levels of transforming growth factor β (Tgfb), zinc finger E-box binding homeobox 2 (Zeb2) and collagen type I alpha 1 chain (Col1a1), all of which are associated with fibrosis.