This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
Anti U1-14NP antibody is seen in?- 
Select and explain. 
A. SLE, B. Scleroderma, C. MCTD, D. Dermatomyositis
C: MCTD
Answer: C: MCTD 
Explanation: Robbins basic pathology 9th edition page no 135,Heading =Mixed connective tissue disease Mixed connective tissue disease have high titers of antibodies to an RNP antigen called U1RNP. This disease also have features suggestive of SLE, polymyositis, orSS.