14868
Insulin receptors ( IRs ) , insulin like growth factor receptors ( IGF - 1R ) and their hybrid receptors belong to tyrosine kinase receptor ( TKR ) family , constitute a structural homology among them and generate a growth promoting IGF system on binding with either insulin , IGF - 1 or IGF - 2 .
 Chemical: tyrosine
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: tyrosine 
Answer:
 Chemical: tyrosine