600
Cytotoxic T lymphocyte - associated antigen 4 ( CTLA - 4 , also known as CD152 ) has been shown to play a major role in the regulation of T cell activation .
 None
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:  
Answer:
 None