tigens were detected according to their molecular weight by western blotting and the most consistently reported eye muscle membrane proteins recognized by serum autoanti-bodies in TAO patients were proteins of 55 and 64 kDa.[@b24-opth-4-417] The 55 kDa protein, later called G2s,[@b25-opth-4-417] was recognized to be a fragment of the FOX-P1 transcription factor {human genome project}. It was also demonstrated that there were in fact three 64 kDa proteins; Fp, the 1D protein and calsequestrin.[@b26-opth-4-417] In our earlier studies, using a crude preparation of calsequestrin prepared from rabbit heart muscle and by measuring corresponding calsequestrin antibodies by western blot analysis we found a modest relationship between anti-calsequestrin antibodies and ophthalmopathy. Anti-calsequestrin antibodies were detected in 40% of patients with clinically active TAO but only in 5% of normal subjects.[@b27-opth-4-417] In a separate study we demonstrated that anti-G2s antibodies were also associated with active ophthalmopathy in patients with Graves' hyperthyroidism, being detected in 54% of patients with active TAO compared to 33% of those with inactive disease. Anti-G2s antibody detection was shown to precede the development of congestive ophthalmopathy in 7 out of 8 patients and ocular myopathy in 6 out of 7 patients.[@b28-opth-4-417] In patients with Graves' hyperthyroidism, early studies also highlighted the role of Fp as a potential marker of eye muscle inflammation. Anti-Fp antibodies were detected in 66% of patients with ophthalmopathy and eye muscle involvement and in 32% of patients with congestive ophthalmopathy.[@b28-opth-4-417] Fp antibody positivity was also shown to precede the development of ocular myopathy, but not congestive ophthalmopathy, in 5 out of 6 patients.[@b28-opth-4-417]

Although these initial studies seemed to demonstrate that antibodies against Fp and G2s were closely linked to the eye muscle component of ophthalmopathy neither are specific to the eye muscle and both antigens are express