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
In pemphigus circulating antibodies attack: 
Select and explain. 
A. Desmoglein 1&2., B. Desmoglein1&3., C. Desmoglein1&4., D. Desmoglein2&4.
B: Desmoglein1&3.
Answer: B: Desmoglein1&3. 
Explanation: Pemphigus

Is a skin and mucous membrane disease with autoimmune etiology.
Characterized histologically by intradermal blisters circulating IgG (IgG1 and IgG4) antibody against keratinocyte cell surface (attack Desmoglein 1 and 3).