In this study, we demonstrate that (1) IL-6 is induced in the kidney in response to obstructive injury; (2) WT and IL-6 KO mice accumulate similar number of bone marrow-derived fibroblast precursors in the kidney following obstructive injury; (3) Targeted disruption of IL-6 has no significant effect on myofibroblast formation and α-SMA expression; (4) Targeted disruption of IL-6 does not influence gene expression of profibrotic chemokines and cytokines; (5) Targeted disruption of IL-6 does not alter the severity of renal fibrosis and the expression of ECM proteins. This evidence concerns the gene ACTA1 and renal fibrosis.