The most frequent symptoms in PBC are fatigue and pruritus, occurring in up to 85% and 70% of patients, respectively [8, 9] . Median survival in untreated individuals has been reported to be 7.5 to 16 years [1, 10] , but has largely improved since the introduction of ursodeoxycholic acid (UDCA) therapy and liver transplantation. Patients that are treated with UDCA at an early stage of the disease and respond well to therapy may reach normal life expectancy [11] [12] [13] [14] . However, the beneficial mechanisms of UDCA treatment are still incompletely understood, and about one third of patients fail to adequately respond to UDCA monotherapy. In the second part of this review, we will therefore summarize the rationale behind UDCA therapy and give an overview on future therapeutic options currently under study.