CTLA4 and autoimmune disease: Indeed, as evidenced in our previous study and in numerous others, several CTLA-4 polymorphisms that may influence gene expression, lead to amino acid substitution, and alter mRNA splicing have been linked with susceptibility to autoimmune diseases, including autoimmune thyroid diseases, systemic lupus erythematosus, rheumatoid arthritis, and type 1 diabetes [9–15].