KIT and intrahepatic cholangiocarcinoma: All the cells identifiable as ICC for their shape and region-specific location [10–17], i.e. the ICC located in the region around myenteric ganglia and between the two muscle layers (ICC-MP; Fig. 5A and B), the ICC at the submucosal border of the gastric and colonic circular muscle layer (ICC-SM; Fig. 6B and C), the intramuscular ICC (ICC-IM; Fig. 6D), and the ICC at the deep muscular plexus (ICC-DMP; Fig. 6E), were c-kit-positive.