406
These results suggest that (1) the differentiation inhibitory activity of I-factor /nm23 protein is not restricted to monocytic differentiation of M1 cells , (2) the inhibitory activity is exhibited without species specificity, and (3) the differentiation inhibitory activity of the nm23/NDP kinase protein is independent of its enzyme activity and requires the presence of N-terminal peptides .
 protein: nm23/NDP kinase protein; cell line: M1 cells; protein: I-factor; protein: I-factor /nm23 protein
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: nm23/NDP kinase protein, M1 cells, I-factor, I-factor /nm23 protein 
Answer:
 protein: nm23/NDP kinase protein; cell line: M1 cells; protein: I-factor; protein: I-factor /nm23 protein