5716
Previously we reported the identification of NA255 from our natural products library using a HCV sub - genomic replicon cell culture system .
 Chemical: NA255
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: NA255 
Answer:
 Chemical: NA255