TIMP-1 production is reduced in STAT3Hep-/- mice during chronic liver injury. A, Mice were treated with CCl4 for 4 weeks and euthanized at various time points. Liver tissues were collected and analyzed for TIMP-1, TIMP-2, TIMP-3 and MMP-9. Value from wild-type mice without CCl4 treatment was set as 1. B, Serum levels of TIMP-1 protein at various time points post 4-week-CCl4 treatment. *P < 0.05 in comparison with the corresponding wild-type groups.