898
Here we focused on the role of the 5 ' proximal regulatory cassette ( - 190 ; + 53 bp ) of the rat enkephalin ( rENK ) gene in the developmental regulation of the enkephalin phenotype .
 GENE: rat enkephalin; GENE: rENK; GENE: enkephalin
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: rat enkephalin; GENE: rENK; GENE: enkephalin