COL1A1 and Hepatic fibrosis: Consistently, the upregulation of hydroxyproline, serum ALT and AST levels, and hepatic protein level of α-SMA and mRNA levels of Col1α1, Acta2 and TIMP-1 were also increased in IFN-γ-/- Vγ4 cells reconstituted mice (Fig. 1j–n), while IL-17-/- γδ T cells still showed protection against hepatic fibrosis (Fig. 1h–n).