E2F stands for family of transcription factors (TF) in higher eukaryotes. Three of them are activators: E2F1,2 and E2F3a. Six others act as suppressors: E2F3b, E2F4-8. All of them are involved in cell cycle regulation and synthesis of DNA. E2F TFs bind to the TTTCGCGC consensus binding site in the target promoter sequence.