An interesting link between primary cilia and β-cell polarity was revealed by a model of liver kinase B1 (LKB1) deficiency (15), which models the genetic defect in human Peutz-Jeghers syndrome, an autosomal dominant germline disease manifested by intestinal polyposis and pancreato-biliary cancers (64–66). The gene discussed is STK11; the disease is Peutz-Jeghers syndrome.