24399
Accumulating evidence suggests involvement of serotonin ( 5 - HT ) in the regulation of emotion .
 Chemical: serotonin; Chemical: 5 - HT
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: serotonin; Chemical: 5 - HT