TRIM21 and systemic lupus erythematosus: Furthermore, AT-rich interactive domain-containing protein 2 (ARID2 or BAF200), a subunit of the polybromo-associated barrier-to-autointegration factor (PBAF) chromatin-remodeling complex, which is known to regulate the expression of multiple interferon-responsive genes [52], was elevated in the SSA/SSB+ SLE subgroup.