IFIH1 and arthritic joint disease: Anti-Jo-1 was associated with a unique clinical subset characterized by myositis, arthritis, mechanic’s hands, Raynaud’s phenomenon, and chronic progressive ILD [35], while anti-MDA5 is always present in clinically amyopathic dermatomyositis (CADM), having typical DM skin rash and increased serum levels of ferritin but little or no muscle involvement [33, 36-39].