Disturbance of ependymal integrity induces hydrocephalus in other mouse models, for example, mice deficient for Myo9a, Pkcl, Numbl, Ophn1, Myh4, Dlg5, or Mdnah5 (Ibañez‐Tallon et al, 2004; Imai et al, 2006; Kuo et al, 2006; Khelfaoui et al, 2007; Ma et al, 2007; Nechiporuk et al, 2007; Abouhamed et al, 2009). Here, OPHN1 is linked to Hydrocephalus.