The presence of two distinct propulsive motor patterns in the mouse small intestine was confirmed in studies on the WWv mouse that has a spontaneous mutation that inhibits expression of the c-kit protein resulting in a 95% reduction in ICC-MP and absence of ICC-MP-induced slow waves (Huizinga et al., 1995; Malysz et al., 1996). The gene discussed is KIT; the disease is intrahepatic cholangiocarcinoma.