Telomere-binding protein that acts as a regulator of telomere length (PubMed:28500257, PubMed:28082411). Directly binds the telomeric double-stranded 5'-TTAGGG-3' repeat (PubMed:28500257, PubMed:28082411). Preferentially binds to telomeres that have a low concentration of shelterin complex and acts as a regulator of telomere length by initiating telomere trimming, a process that prevents the accumulation of aberrantly long telomeres (PubMed:28082411). Also acts as a transcription regulator that binds to promoter regions (PubMed:7969177, PubMed:24382891, PubMed:28500257). Regulates expression of a small subset of genes, including MTFP1 (PubMed:28500257). Regulates expression the J and/or S elements in MHC II promoter (PubMed:7969177). Acts as a negative regulator of cell proliferation by specifically activating expression of ARF, a tumor suppressor isoform of CDKN2A (PubMed:24382891). Interacts with EP300 (PubMed:24382891). Directly binds the telomeric double-stranded 5'-TTAGGG-3' repeat (PubMed:28500257, PubMed:28082411). According to a report, preferentially binds to long telomeres that have a low concentration of shelterin complex, competing with the telomeric repeat binding factors TERF1 and TERF2 (PubMed:28082411). According to another report, binds telomeres regardless of their length (PubMed:28500257). Detected in adrenal gland and neuroblastoma. The C2H2-type zinc fingers mediate binding to the telomeric double-stranded 5'-TTAGGG-3' repeats (PubMed:28082411). The last C2H2-type zinc finger is required for telomeric-binding (PubMed:28500257). Belongs to the krueppel C2H2-type zinc-finger protein family. According to a study, preferentially binds to long telomeres that have a low concentration of shelterin complex (PubMed:28082411). According to another report, binds telomeres regardless of their length (PubMed:28500257).