Our results showed that the knockdown of NR4A1 can accelerate unilateral ureteral obstruction (UUO)-induced renal fibrosis in mice, and overexpression of NR4A1 can significantly reduce transforming growth factor-β1-induced (TGF-β1) fibrosis in HK-2 cells. The gene discussed is TGFB1; the disease is Ureteral obstruction.