CD226 and rheumatoid arthritis: CD226 rs763361/gly307ser non-synonymous mutations are associated with susceptibility to autoimmune diseases such as type 1 diabetes (T1D), rheumatoid arthritis (RA), multiple sclerosis (MS), autoimmune thyroid disease (AITD), and systemic sclerosis (SSc; Todd et al., 2007; Qiu et al., 2008; Smyth et al., 2008; Dieudé et al., 2011).