14760
Vesicular stomatitis virus G glycoprotein ( VSV - G ) is the most widely used envelope protein for retroviral and lentiviral vector pseudotyping ; however , serum inactivation of VSV - G pseudotyped vectors is a significant challenge for in vivo gene delivery .
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Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
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