Owing to their morphological and proposed functional similarities to Kit+ interstitial cells of Cajal (ICC) in the gastrointestinal tract, which serve as smooth muscle pacemakers [79] and neuromodulators [80], this manuscript will collectively refer to such interstitial cells in the urethra as ICC-like cells (ICC-LC) [8]. The gene discussed is KIT; the disease is intrahepatic cholangiocarcinoma.