5438
BACKGROUND : We conducted a phase I study with MDL 73 , 147EF , a new 5 hydroxytryptamine 3 ( 5 - HT3 ) receptor antagonist , in 25 patients requiring emetogenic chemotherapy .
 GENE: 5 hydroxytryptamine 3 ( 5 - HT3 ) receptor
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
 Entities: 5 hydroxytryptamine 3 ( 5 - HT3 ) receptor 
Answer:
 GENE: 5 hydroxytryptamine 3 ( 5 - HT3 ) receptor