GTF2A2 and rheumatoid arthritis: Interestingly, anti-GTF2A2 was the only autoantibody found to be higher in both ACPA+ RA and ACPA − RA; this provides further evidence of previously reported immunological differences between these two subgroups despite sharing similar symptoms5,38, although the precise pathophysiological mechanisms—or potential influences of genetic predisposition39,40—remain yet unclear.