Mutations in Nek1 are causal in the murine models of polycystic kidney disease kat and kat2J, resulting in a recessive pleiotropic phenotype that includes progressive cystic kidneys, male sterility, dwarfing, abnormal olfactory lobes, facial dysmorphism, choroid plexus cysts, hydrocephalus, uremia and anemia [2-4]. The gene discussed is NEK1; the disease is polycystic kidney disease.