Transcription activator that binds DNA elements with the consensus sequence 5'-CGGTAATTGG-3'. Binds DNA via its homeobox. Required for normal cell death of enteric neurons in the gastrointestinal tract. Required for normal development of the enteric nervous system, and for proper development of normal motility of the gastrointestinal tract. Detected in cranial ganglia at 9 dpc, and in dorsal root ganglia by 10.5 dpc. First detected in gut at 11.5 dpc, with a marked increase by 12.5 dpc. After birth, detected in myenteric and submucosal neurons innervating the distal ileum, colon and rectum. Mice are born at the expected Mendelian ratio and show no visible phenotype at birth. After weaning, about 43% of the mice exhibit distended abdomens and growth retardation, the others remain symptomless. About 36% of the mice die between 3 and 6 weeks after birth. Affected mice display distended proximal colons and cecums. Both affected and asymptotic mice have increased numbers of myenteric neurons in ganglia in the proximal and distal colon with a concomitant increase in myenteric ganglion size. In the urinary system, mice exhibit increased numbers of NADPH diaphorase positive neuronal cells in the vesical ganglia, and concomitant vesicourethral sphincter muscle dysfunction. Was originally thought to be the ortholog of human HOX11.