Loss-of-function mutations within the Kit or Scf locus (e.g., W/Wv, Sl/Sld and W(jic)/W(jic)) have been used to study the absence of certain types of ICC throughout the GI muscle, showing phenotypes including disrupted pacemaker activity [23,47,48]. The gene discussed is KIT; the disease is intrahepatic cholangiocarcinoma.