Paired homeobox protein 2B (PHOX2B) is a transcription factor located on chromosome 4p13, which is essential for forming autonomic ganglia in the autonomic nervous system. PHOX2B is expressed in neuroblastoma, brain, and adrenal glands. PHOX2B deficiency can lead to susceptibility to congenital central hypoventilation syndrome (CCHS) and neuroblastoma type 2 (NBLST2).