TNFRSF13C and synovial sarcoma: Moreover, the rs2230926 exonic variant of the Tumor Necrosis Factor, Alpha-Induced Protein 3 (TNFAIP3) gene, encoding a defective A20 protein, along with the BAFF-R His159Tyr mutation, have been detected in increased frequency among young SS patients (≤40 years) complicated with lymphoma [27,28].