NaV1.9 expression has also been shown in myenteric and submucosal plexuses in normal human colon, and reduced NaV1.9 expression has been reported in ganglionic tissue from patients with Hirschsprung’s disease (O’Donnell et al., 2016), supporting a contribution of NaV1.9 in GI function. This evidence concerns the gene SCN11A and Hirschsprung disease.