TRF2 is a ubiquitously expressed protein that is implicated in the control of telomere length. TRF2, like TRF1, contains a Myb-related DNA binding motif. It binds to duplex TTAGGG repeats and is localised to all human telomeres in metaphase chromosomes. TRF2 is thought to protect chromosome ends by maintaining the correct structure at telomere termini. The use of mutant forms of TRF2 has implicated a role for TRF2 in the prevention of senescence in primary human cells. Recently, it has been shown that inhibition of TRF2 resulted in apoptosis in a subset of mammalian cell types. TRF2 is overexpressed in a number of human tumors and overexpression of TRF2 has been shown to be oncogenic in a mouse model of carcinogenesis.