In the hematopoietic stem cell transplant population, those who received 50 to 60 days of oral ciprofloxacin prophylaxis at 500 mg twice daily demonstrated a decrease in peak BK viruria early after transplantation (range: 7–39 days) and significantly lower rates of hemorrhagic cystitis [13, 14]. Here, KNG1 is linked to hemorrhagic cystitis.