Myositis-specific antibodies (MSAs), such as anti-MDA5, Mi-2, TIF1γ, Jo-1, NXP2, and anti-aminoacyl-tRNA synthetase (ARS), and myositis-associated antibodies (MAAs), such as anti-Ro52, anti-PM/Scl, and anti-Ku, are pivotal in diagnosing, prognosticating, and managing IIM, even when muscle involvement is absent [1]. Here, TRIM21 is linked to myositis disease.