In a study investigating the role of CX3CL1/CX3CR1 axis in PBC, a condition prompting to CCA [199], CX3CL1 was found over-expressed in injured bile ducts, whereas the number of CX3CR1+ mononuclear cells infiltrated into portal tracts was highly increased [96]. This evidence concerns the gene CX3CL1 and primary biliary cholangitis.