9397
Recently, cyclin E-Cdk2- and cyclin A-Cdk2- dependent phosphorylation of a single conserved serine residue ( Ser5 ) in Id2 has been shown to occur during late G1-to-S phase transition of the cell cycle, and this neutralizes the function of Id2 in abrogating E-box-dependent bHLH homo -or hetero dimer complex formation in vitro (E.Hara, M.Hall, and G.Peters, EMBO J.16:332-342, 1997).
 Id2, Id2, E-box-dependent bHLH
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:
 Id2, Id2, E-box-dependent bHLH