An extended myositis antibody panel demonstrated positivity for anti-PL-12 antibodies, a defining serological marker of ASyS; other myositis-specific and associated antibodies, including anti-Mi-2, anti-Ku, anti-polymyositis/Scleroderma 70 (PM-SCL 70), anti-centromere, anti-Jo-1, anti-signal recognition particle (SRP), anti-PL-7, and anti-Ej, were negative. This evidence concerns the gene PARTICL and myositis disease.