AFDN and Hydrocephalus: Although it was not known whether the genetic deletion of these molecules causes the stenosis or obliteration of the cerebral aqueduct or the third ventricle, it would cause the phenotypes similar to those observed in the genetic deletion of afadin. The present results together with these earlier observations make it evident that AJs in neuroepithelial cells, radial glial cells, and ependymal cells lining the ventricular and aqueductal walls are essential for maintaining the physical and normal functions of these cells and for preventing hydrocephalus.