TGM2 and type 1 diabetes mellitus: Prototypical examples are neo(ex-self)-antigens in type 1 diabetes (T1D) (i.e., tissue transglutaminase-dependent deamidation or alternative-reading-frame-encoding of pro-insulin peptides), or in rheumatoid arthritis (i.e., citrullination or deamination of vimentin, lamin B1, non-muscle myosin, actin and other cytoskeleton or nuclear self-antigens) (93–98).