SNRNP70 and myositis disease: The jSSc patients with overlap syndrome and associated antibodies (U1-RNP, Pm-Scl, U3-RNP) that have myositis may be of the most concern, as myopathy of the peripheral skeletal muscle is likely related to cardiac skeletal myopathy, and these patients have been demonstrated to have more conduction defects and other cardiac manifestations, a major contributor to mortality (6, 12, 13, 18).