Plays a role in the reduction of telomerase activity during differentiation of embryonic stem cells by binding to the core promoter of TERT and controlling its down-regulation. Interacts with PPP1CA and NCOA5. Forms a complex with ILF2, ILF3, KHDRBS1, RBMX, NCOA5 and PPP1CA (By similarity). Migrates to nucleolar caps upon blockage of transcription. Expressed in the 7.5 dpc embryos.