Transcription factor. Binds to the oxygen responsive element of COX4I2 and activates its transcription under hypoxia conditions (4% oxygen), as well as normoxia conditions (20% oxygen) (PubMed:23303788). Interacts with RBPJ. Mainly localized in the intermembrane space. Up-regulated by hypoxia (4% oxygen) (at protein level). Mutations in CHCHD2 are rare, and might vary by ethnic origin. The gene represented in this entry may be involved in disease pathogenesis.