1682
The nuclear proteins encoded by the c - fos and c - jun protooncogenes are expressed during the proliferation period of osteoblast phenotype development .
 c - fos, c - jun protooncogenes
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 c - fos, c - jun protooncogenes