For example, interleukin-8 (IL-8) was thought to be a UDB [4] as it was reported to be a useful biomarker for multiple diseases including urinary bladder cancer, prostatitis, acute pyelonephritis, vesicoureteral reflux, pulmonary infections, osteomyelitis, inflammatory bowel disease, chorioamnionitis, nosocomial bacterial infections, and non-Hodgkin’s lymphoma. The gene discussed is CXCL8; the disease is male reproductive organ cancer.