Approximately 5% of Sjögren’s syndrome patients have cerebellar atrophy, with Purkinje cells predominantly affected, consistent with the observation that TRIM21 expression, whilst generally low, is enriched in Purkinje neurons of the hippocampus, cerebral cortex, and cerebellum (Zhang et al., 2014; Uhlén et al., 2015; Tetsuka et al., 2021). This evidence concerns the gene TRIM21 and Sjogren syndrome.