该基因编码一个转录因子，参与氧调节基因的诱导，随着氧水平的下降而诱导。编码蛋白包含一个基本的螺旋-环-螺旋结构域蛋白二聚结构域以及一个在信号转导途径中发现的对氧水平有反应的结构域。该基因突变与红细胞增多症家族性4型有关。

This gene encodes a transcription factor involved in the induction of genes regulated by oxygen, which is induced as oxygen levels fall. The encoded protein contains a basic-helix-loop-helix domain protein dimerization domain as well as a domain found in proteins in signal transduction pathways which respond to oxygen levels. Mutations in this gene are associated with erythrocytosis familial type 4.