IFIH1 and myositis disease: Serum myositis antibody panel negative for anti-Jo-1 antibody, anti-PL-7 antibody, anti-PL-12 antibody, EJ, OJ, anti-MI-2α antibody, anti-MI-2β antibody, anti-MDA5 antibody, anti-TIF1γ antibody, anti-NXP2 antibody, anti-SAE1 antibody, SRP, anti-RO-52 antibody, anti-PM-SCL75 antibody, anti-PM-SCL100 antibody, and anti-KU antibody, and without myalgia or elevated creatine kinase levels, ruling out myositis.