The function of E2F4 (E2F transcription factor 4, Ensembl gene identifier ENSG00000205250) is as follows. Transcription activator that binds DNA cooperatively with DP proteins through the E2 recognition site, 5'-TTTC[CG]CGC-3' found in the promoter region of a number of genes whose products are involved in cell cycle regulation or in DNA replication. The DRTF1/E2F complex functions in the control of cell-cycle progression from G1 to S phase. E2F4 binds with high affinity to RBL1 and RBL2. In some instances can also bind RB1. Specifically required for multiciliate cell differentiation: together with MCIDAS and E2F5, binds and activate genes required for centriole biogenesis. {ECO:0000250|UniProtKB:Q6DE14, ECO:0000269|PubMed:7958924, ECO:0000269|PubMed:7958925}.