1659
Critical residues required for repression are located within the C - terminal 27 amino acids of c - Fos , since v - Fos and C - terminal truncations of c - Fos did not down regulate .
 c - Fos, v - Fos, c - Fos
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 c - Fos, v - Fos, c - Fos