Yeker RM, et al. - An inquiry was set up with regard to the prevalence and clinical features related to anti-NT5C1A autoantibodies in juvenile myositis. More than one-quarter of children with juvenile myositis and juvenile idiopathic arthritis (JIA) presented with anti-NT5C1A autoantibodies when compared to only 12% of healthy children. This, in turn, pointed out that they are myositis-associated in children. Similar to adults with inclusion body myositis (IBM), patients with juvenile myositis with anti-NT5C1A autoantibodies exhibited a more severe disease.