IFT81 and cystic kidney disease: Unlike many other IFT encoding genes, no mouse model has been reported for Ift81. However, an ift81 zebrafish mutant (hi409/larry) was first identified in a genetic screen for fish with cystic kidney disease.28 Somite-stage gene expression showed enrichment along classically ciliated organs; notochord, otic vesicle, pronephric duct, and around the cerebral ventricles, pointing towards an essential role of IFT81 in embryonic development of kidneys and brain.28 This is consistent with the view that IFT81 mutations can cause a ciliopathy in humans.