The nonsynonymous single nucleotide polymorphism (SNP) rs763361/Gly307Ser in exon 7 of CD226 leads to the substitution of serine for glycine in the amino acid sequence of CD226 and has been associated with increased risk for type 1 diabetes, MS, rheumatoid arthritis and autoimmune thyroid disease [5]. Here, CD226 is linked to rheumatoid arthritis.