Villalta et al evaluated the prevalence of IgA and IgG anti tTG in 47 autoimmune hepatitis patients, 120 blood donors and 100 chronic hepatitis C cases, and found only one HCV patient positive for IgG anti-tTG, but negative for IgA EMA (16); however, this case was considered as a false positive because HLA DQ2-DQ8 typing was negative. This evidence concerns the gene TGM2 and autoimmune hepatitis.