RNPC3 and mixed connective tissue disease: MCTD is distinguished from other overlap syndromes in that it has positive anti-RNP antibodies.1 The current standard of care recommends corticosteroids to control signs and symptoms of MCTD, as there is no cure.2 Major organ involvement may require high doses of corticosteroids and cytotoxic agents such as cyclophosphamide.2 Medications are prescribed to achieve presenting symptom control.