This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'In pemphigus circulating antibodies attack: \nSelect and explain. \nA. Desmoglein 1&2., B. Desmoglein1&3., C. Desmoglein1&4., D. Desmoglein2&4.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Pemphigus\n\nIs a skin and mucous membrane disease with autoimmune etiology.\nCharacterized histologically by intradermal blisters circulating IgG (IgG1 and IgG4) antibody against keratinocyte cell surface (attack Desmoglein 1 and 3).', 'role': 'assistant'}]