TLR4 and renal fibrosis: The unilateral ureteral obstruction (UUO) model is often used in the context of renal fibrosis [20], [21] and data from TLR2– or TLR4-deficient mice propose that TLR signaling contributes to postobstructive renal inflammation, tubular atrophy, and interstitial fibrosis [22], [23].