TRF2, also named as TRBF2 and Telomeric repeat-binding factor 2, is a 542 amino acid protein, which contains 1 HTH myb-type DNA-binding domain and localizes in the Nucleus. TRF2 binds the telomeric double-stranded 5'-TTAGGG-3' repeat and plays a central role in telomere maintenance and protection against end-to-end fusion of chromosomes. TRF2 is a component of the shelterin complex (telosome) that is involved in the regulation of telomere length and protection. TRF2 together with DCLRE1B/Apollo, is required to control the amount of DNA topoisomerase (TOP1, TOP2A and TOP2B), which is needed for telomere replication during fork passage and prevent aberrant telomere topology. TRF2 recruits TERF2IP/RAP1 to telomeres, thereby participating in to repressing homology-directed repair (HDR), which can affect telomere length.