Even though it has been reported that the β-AR-agonist isoproterenol is involved in the regulation of ICC functions (Morel et al., 1976; Iino et al., 1981; Morel and Doucet, 1986; Hayashi et al., 1991; DiBona and Kopp, 1997), the role of the sympathetic nervous system in controlling acid–base balance still needs to be elucidated. The gene discussed is ADRB2; the disease is intrahepatic cholangiocarcinoma.