GFRA1 and dentin dysplasia: Whereas the myenteric expression level of GDNF did not differ significantly in patients with diverticulosis and DD when compared to controls (Fig 3A), the myenteric expression of GFRA1 significantly decreased to 47% ± 8% of control values in patients with diverticulosis and to 28% ± 11% of control values in patients with DD (Fig 3B).