PHOX2B is a gene that plays a crucial role in the development of the nervous system, particularly in the formation of certain neurons. It is essential for the proper functioning of the autonomic nervous system, which controls involuntary bodily functions such as heart rate and breathing. Mutations in the PHOX2B gene can lead to various health conditions, including Congenital Central Hypoventilation Syndrome (CCHS), a disorder that affects the ability to breathe normally during sleep. Understanding PHOX2B is important for diagnosing and managing these conditions effectively.