TRIM21 and systemic sclerosis: The prevalence of antibodies in the examined population of SSc patients was: ATA (36%), Ro-52 (28%), PM-Scl-75 (20%), CENP-B (22%), CENP-A (20%), PM-Scl-100 (14%), fibrillarin (7%), Th/To (7%), RNA polymerase III 11 kDa (5%), PDGFR (3%), NOR-90 (2%), RNA polymerase III 155 kDa (3%), and Ku (1%).