Bloch et al. (2006) also discovered that AQP4 can exacerbate hydrocephalus in kaolin-induced H-t gene deletion rats (congenital AQP4 protein deficiency rats) by decreasing the rate of extracellular fluid clearance across the blood-brain barrier, indicating that AQP4 plays a beneficial role in increasing the blood-brain barrier clearance rate and preventing the accumulation of excess water in the ventricles. The gene discussed is AQP4; the disease is Hydrocephalus.