In patients with autoimmune thyroid disease, the levels of expression of soluble CTLA-4 are as much as 7- to 20-fold greater than in normal individuals;14 furthermore, individuals suffering from myasthenia gravis,15 systemic lupus erythematosus16 and systemic sclerosis17 also show elevated soluble CTLA-4 expression. Here, CTLA4 is linked to myasthenia gravis.