This gene encodes a protein containing a basic helix-loop-helix domain and two characteristic PAS domains along with a PAC domain. The encoded protein binds to ligand-bound aryl hydrocarbon receptor and aids in the movement of this complex to the nucleus, where it promotes the expression of genes involved in xenobiotic metabolism. This protein is also a co-factor for transcriptional regulation by hypoxia-inducible factor 1. Chromosomal translocation of this locus with the ETV6 (ets variant 6) gene on chromosome 12 have been described in leukemias. Alternative splicing results in multiple transcript variants.,ARNT,HIF-1-beta,HIF-1beta,HIF1-beta,HIF1B,HIF1BETA,TANGO,bHLHe2,Epigenetics & Nuclear Signaling,Transcription Factors,Nuclear Receptor Signaling,Cancer,Invasion and Metastasis,Signal Transduction,mTOR Signaling Pathway,Endocrine & Metabolism,Nucleotide metabolism,Cardiovascular,Angiogenesis,Hypoxia,HIF,ARNT