IFIH1 and rheumatoid arthritis: Systemic sclerosis (SSc) ILD was the most investigated condition (58%, 19/33 studies) followed by anti-melanoma differentiation-associated protein 5 (MDA5) dermatomyositis (12%, 4/33 studies), rheumatoid arthritis (RA) ILD (2%, 4/33 studies) and idiopathic inflammatory myopathies (9%, 3/33 studies).