UPK2 and hydronephrosis: The majority (about 60%) of UPII-mutant Ha-ras mice developed hydronephrosis and obstructive ureters, and there was less uropathy in the mice that drank SHR-5 (50 and 30% for 1.25 and 6.25 mg/mL SHR-5, respectively) (Figure 4A,B).