The E2F1 gene transcription is inhibited by binding of E2F6 to the E2F1 gene promoter (Yang et al. 2008). E2F6 is assumed to be in the complex with at least TFDP1 or TFDP2. The E2F6.com-1 complex, consisting of E2F6, TFDP1 (DP-1), MGA, MAX, EHMT1 (GLP) and EHMT2 (G9a), associated with CBX3 (HP1gamma) and probably the PRC1.6 complex, also binds to the E2F1 gene promoter. While repression of E2F1 transcription by the E2F6.com-1 complex has not been examined, this complex is thought to introduce repressive H3K9Me epigenetic marks on chromatin. Therefore, E2F6.com-1 complex is shown as a candidate repressor of the E2F1 gene transcription (Ogawa et al. 2002). E2F6-mediated repression of E2F1 is implicated in inhibition of cell cycle entry and maintenance of G0 state (cellular quiescence) (Ogawa et al. 2002), which has been challenged by more recent studies (Giangrande et al. 2004, Bertoli et al. 2013, Bertoli et al. 2016), but also in the inhibition of E2F1-mediated apoptosis (Yang et al. 2008).