9397
In addition , the regulation of Glvr - 1 gene expression also has potential applications to gene therapy , since retroviral vectors carrying gibbon ape leukemia virus envelope proteins are used for gene delivery into different cell types .
 Glvr - 1 gene, gibbon ape leukemia virus envelope proteins
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 Glvr - 1 gene, gibbon ape leukemia virus envelope proteins