Complement factor C5 deficiency significantly delays the progression of biliary fibrosis in bile duct-ligated mice

► C3 is activated during biliary obstruction in both WT and C5-deficient mice. ► C5 significantly attenuates the amount of fibrosis in response upon BDL. ► C5-deficient mice show decreased expression of fibrosis-associated genes and TNF-α. ► Reduced peribiliary infiltration of leucocytes in fibrotic areas with C5 deficiency. ► Decreased expression of MMP-9 and decreased gelatinase activity in C5-deficient mice.