**5.6 p110 CUX1**

Cut homeobox 1 (CUX1) proteins are transcription factors that can either activate or repress transcription. In particular, the CUX1 isoform p110 can stably interact with DNA and promote entry into the S-phase of the cell cycle (Truscott et al., 2008). P110 CUX1 interacts with E2F-1 or E2F-2, stimulating their recruitment to the DNA polymerase α gene promoter, in a manner that requires ability of E2F to bind DNA. Further, common targets for E2F and p110 CUX1 include genes involved in cell cycle progression, DNA repair and replication (Truscott et al., 2008).
