TRIM21 and systemic lupus erythematosus: RBPs can also be recognized as autoantigens, and anti-RBP antibodies are frequently detected in patients of AIDs such as SLE.235 For example, anti-Sm antibodies that interact with U1, U2, U4 and U5 RNA snRNPs are predictive for SLE classification; anti-SS-A (Ro52/Ro60) autoantibodies are described as serological markers for Sjögren’s syndrome but also detected in other AIDs.