TRIM21 and polymyositis: The samples covered all subgroups with the most established ANA antigens, including dsDNA, ssDNA (single-stranded DNA), U1RNP (U1 nuclear ribonucleoprotein particle), CENP-B (centromere protein B), RO-52 (Ro/SS-A-p52), RO-62 (Ro/SSA-p60), SSB (La/SS-B), SCL (Scl70/topoisomerase), PM/SCL (polymyositis/scleroderma), DFS70 (dense fine speckles), HIAK (histone), NUCLEO (nucleosome), FBLN (fibrillarin), and RPOI (RNA polymerase I–III).