Patients with PBC show increased expression of FKN in the biliary epithelial cells, as well as aggregation of monocytes and lymphocytes with CX3CR1 expression within the damaged bile duct, suggesting that the FKN/CX3CR1 signal also plays an important role in the pathogenesis and progression of PBC [19]. This evidence concerns the gene CX3CL1 and primary biliary cholangitis.