5514
For HeLa , 293 , U937 , and A549 cells , participation of E2F - 1 , DP - 1 , cyclin A , and RB was involved in formation of some complexes only , assuming participation of factors different from E2F - 1 or DP - 1 in others .
 E2F - 1, DP - 1, cyclin A, RB, E2F - 1, DP - 1
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 E2F - 1, DP - 1, cyclin A, RB, E2F - 1, DP - 1