Several studies have reported elevated expression of AQP4 in connection with hydrocephalus, including congenital hydrocephalus in Texas rats (Paul et al., 2011), idiopathic communicating internal hydrocephalus in dogs (Schmidt et al., 2016), and inflammatory communicating hydrocephalus in rats (Tourdias et al., 2009). The gene discussed is AQP4; the disease is congenital hydrocephalus.