ARNT encodes aryl hydrocarbon receptor nuclear translocator containing a basic helix-loop-helix domain and two characteristic PAS domains along with a PAC domain. Aryl hydrocarbon receptor nuclear translocator 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. Aryl hydrocarbon receptor nuclear translocator 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.