HIF1A and Ureteral obstruction: For example, Kimura et al. (2008) studied a 5/6 nephrectomy model (removal of one kidney and 2/3 of the other kidney) and found that VHL deletion led to increased HIF-1α expression and increased renal fibrosis, and that the application of anti-HIF-1α drugs inhibited the progression of renal fibrosis in the unilateral ureteral obstruction (UUO) mouse model.