14918
Together these results suggest that the BAT box binding proteins are important in the B cell specific expression of CD20 and perhaps CD21 .
 protein: CD20; protein: BAT box binding proteins; protein: CD21
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
 Entities: CD20, BAT box binding proteins, CD21 
Answer:
 protein: CD20; protein: BAT box binding proteins; protein: CD21