2647
During the biosynthesis of all three mutant polypeptides , the signal peptide is efficiently and accurately cleaved from the nascent protein , even though in mutants X2 and X3 the cleavage site itself has been altered .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
 Entities:  
Answer:
 None