Although, the data of CTLA4 polymorphism and the association between CTLA4 and PBC were not reported in the GWAS of PBC, CTLA4 was the main focus of PBC in many candidate gene studies, and certain benefit results were obtained as a therapeutic target from CTLA4. CTLA4-Ig has been developed as an exciting outcome in mouse model of PBC [11, 12]. Here, CTLA4 is linked to primary biliary cholangitis.