KIT and intrahepatic cholangiocarcinoma: In identifying further correlation to defecation difficulty in aged mice, the intestinal pacemakers, ICC were considered as a possible target due to the ability to control enteric nervous system.44 Freshly prepared young and old colonic cells were stained with antibodies against ICC marker c-kit, and flow cytometry analysis displayed a significant reduction of c-kit positive population in aged colonocytes (Figure 2g; young: 2.65±0.17% versus old: 1.60±0.39%).