TGFB1 and renal fibrosis: However, GS-642362 treatment gave a clear-cut inhibition of renal fibrosis on day 7 UUO as demonstrated by a reduction in total kidney collagen content, reduced interstitial deposition of collagen IV, reduced interstitial accumulation of α-SMA+ myofibroblasts, and reduced kidney mRNA levels of collagen IV, α-SMA, and TGF-β1.