29930
Serotonin transporters ( SERT ) play an essential role in the termination and regulation of serotonin signaling in the brain .
 Chemical: Serotonin; Chemical: serotonin
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: Serotonin, serotonin 
Answer:
 Chemical: Serotonin; Chemical: serotonin