5149
Although a role of p16 in this regulation has been presumed, there is no proof so far that loss of this tumor suppressor gene really affects E2F -mediated regulations.
 p16, tumor suppressor gene, E2F
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 p16, tumor suppressor gene, E2F