3779
The significance of this association is controversial , though the association of C2 deficiency with certain histocompatibility antigens suggests possible linkage to immune response genes .
 Disease: C2 deficiency
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Disease 
Text: {0} 
 Entities: C2 deficiency 
Answer:
 Disease: C2 deficiency