The second study, by Kaji et al,[48] compared 44 SSc subjects (from 2 Japanese institutions and the University of Pittsburgh) with single-specificity anti-Ku antibodies with anti-RuvBL1/2 and anti-PM-Scl-positive subjects, all considered as related to SSc/myositis overlap; 50% had inflammatory myositis and 43% had ILD. This evidence concerns the gene RUVBL1 and systemic sclerosis.