15155
Glial cell line - derived neurotrophic factor ( GDNF ) is a potent growth factor essential to the development , survival , and function of dopaminergic neurons ( Airaksinen and Saarma 2002 ) .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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