IRF1 and Sjogren syndrome: Transcription of TRIM21/Ro52 is upregulated by interferon regulatory factor (IRF)1 and 2 while suppressed by IRF4 and IRF8, which is consistent with the significantly higher level of IRF1 and IRF2 and overexpression of TRIM21/Ro52 seen in patients with Sjögren’s syndrome [24].