AQP4 and obstructive hydrocephalus: Furthermore, the multiplicity of transcription factors, e.g., those of the Rfx family (Rfx1-4), as well as the presence of numerous mechanisms and regulatory interactions between the products of genes involved in cilia development [66], which could lead to compensation for the defects of genes identified in our study, could also help prevent the complete aqueductal stenosis, preventing the development of an obstructive hydrocephalus in our AQP4−/− mice.