Although identification of the mechanisms through which anti-TG2 antibodies cause ataxia was beyond the scope of the present study, our findings that both class1 and class2 scFvs labeled cerebrum and cerebellar blood vessels in immunohistochemistry and that they localized on vessels after injection in the lateral ventricle of brain, suggest that these antibodies may cause ataxia through an antibody-antigen interaction at the vascular level. This evidence concerns the gene TGM2 and Ataxia.