Keay et al. compared urinary APF activity and levels of heparin-binding (HB)-EGF and EGF among 219 IC patients, 113 asymptomatic healthy control patients, and 211 patients with other non-IC urogenital diseases, such as acute bacterial cystitis, chronic prostatitis, OAB, bladder cancer, and prostate cancer. Here, EGF is linked to chronic prostatitis.