GPT and primary biliary cholangitis: Kanno et al [17] identified that the CTLA4 +49 (rs231775) genotype was positively associated with liver damage in primary biliary cirrhosis (PBC) in Japanese populations and that PBC patients with the G/G genotype had significantly higher serum levels of ALT, GGT, and IgM than did patients with the A/A or A/G genotype.