2211
Both mutations were tested in a eukaryotic expression system in which enzyme activities of different mutant PAH enzymes reflect the relative severities of the mutations , although these in vitro activities cannot be translated directly into in vivo hepatic activities .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Disease 
Text: {0} 
 Entities:  
Answer:
 None